I didn't watch much of Jamie Oliver's series about unhealthy eating in America, but one moment does stand out. He went to a school in the most obese state in the US, armed with a basket of vegetables. These he held up, one by one, to the class and asked them to name the vegetable. None of them could. We're not talking about weird things like kohlrabi and jerusalem artichokes, which I probably wouldn't have been able to identify until about four years ago, but your most fundamental foodstuffs. It was particularly heartbreaking to see none of the children able to identify a potato. Yet when Jamie held up a box of chips, they unanimously recognised it, screaming with glee: "FRENCH FRIES!" Jamie again held up the potato next to the chips: "Do you know that this comes from this?" he asked. Blank looks all around.

While this is an extreme example, it is true that in the last few decades we have become detached from where our food comes from. Do we really ever consider, chomping down on a Big Mac and fries, the cows and potatoes that, many many stages back before they became processed rubbish, formed the building blocks of said meal? It's often worst with those everyday, mundane foodstuffs that we take for granted: tomato ketchup is rarely called by its full name - when was the last time you thought about the production process of ketchup? The fact that it actually involves tomatoes? I have a friend who claims to hate tomatoes but will happily cover food in ketchup, which just goes to show how estranged from the original much of our food has become.

So when I was kindly invited by Tracklements, producers of many, many award-winning sauces, relishes, jams, pickles and chutneys, to visit their mustard fields and factory and see how the condiment is produced, I paused and realised that I had absolutely no idea where mustard comes from. Mustard, to most people - including myself at this point - is something bright yellow that comes in a jar or a squeezy bottle, right? I bet that not many people have ever considered the natural raw material that ends up as this viscous yellow substance. It's almost as if mustard is harvested in this state, perhaps from some kind of mustard swamp or a giant mustard plant that you can tap to extract. I know of mustard seeds, and have used them in cooking, but had never really given thought to the fact that mustard is a living, growing crop like any other. I wondered how you turned dry, pebbly mustard seeds into the moist, thick substance you can spread in a ham sandwich or squeeze in a lurid strip onto a plastic-looking hotdog. The trip was fascinating and really opened my eyes.

We were met by Guy Tullberg of Tracklements and taken first to the mustard field, where he explained to us the history of the mustard. 'Tracklements' is a Lincolnshire term for traditional accompaniments for meat and cheese. The company was started by William Tullberg, who in 1970 began to make the first wholegrain English mustard, seeking a variety that did not exist at the time (the only readily available mustards were Colman's yellow or brown). Guy told us that the reason for William's obsession with mustard was that he worked in a sausage factory whose sausages were so disgusting he needed mustard to disguise the taste (a buyer at Tesco pronounced them "revolting", and apparently the specification for the sausage was worse than for prison sausages). Having tried the French

moutard a l'Ancienne

, William came across a mention in John Evelyn's diaries (1641-1697) of what appeared to be the English equivalent. After a few trials and experiments, he started to make the occasional batch of mustard, to serve at sausage and mash parties. Its popularity grew among friends and neighbours until one day he was asked to make a couple of dozen jars for the pub, which he packaged and labelled as 'Urchfont Mustard', and the business developed from there. Guy recalls his father making his first batch of mustard "in a dustbin in the kitchen"; Tracklements now make twelve different types of mustard which they sell to around 1200 delis across the UK, as well as Waitrose and Ocado.

Tracklements still make mustard to the original recipe, derived from John Evelyn's diaries - it includes whole chillies, peppercorns and allspice as well as the mustard seed. "What I love is the idea that all those spices were just coming into people's lives at the time", Guy said. His father, apparently, was visited by Trading Standards after he began making and selling his own mustard. They told him he couldn't call it mustard, because "mustard is bright yellow". William showed the inspector Evelyn's diaries, and apparently the dispute was settled. (Incidentally, the reason a lot of mustard is bright yellow is just because of the addition of turmeric). Technology has moved on somewhat since John Evelyn wrote about mustard, however - his recipe calls for a 'quern', an ancient pair of stones used to grind grains and other foodstuffs (sometimes cannon balls, rolled on a hard stone surface, were used), but Tracklements use an industrial grinder (albeit one that is a quarter of a century old).

The 25-year old mustard grinder, still in business.

"I don't believe there's much new in food," Guy told us. "We think we're great experimenters, but it's all been done before. Just look at onion marmalade - there's a recipe existing for it from the mid-eighteenth century." When Tracklements started making onion marmalade, "Trading Standards all over the country went bananas. So between my father and myself we produced 26 pages of historical facts to show that onion marmalade had existed for years." A similar furore occurred over Tracklements' production of Cumberland Sauce, which Trading Standards objected to because it didn't come from Cumberland. "And yet you wouldn't hold up a bottle of Worcester sauce and complain that it wasn't made in Worcester."

It took a while to convince farmers to plant mustard seed for Tracklements: an incredibly prolific crop, a handful of mustard seeds will produce eight tonnes by its second harvest. Once planted, it is almost impossible to get rid of. One of the oldest cultivated spices, mustard was believed to have been introduced to Britain by the Romans. In 2003, a local farmer agreed to grow it for Tracklements, only two miles from their factory in Wiltshire. A great success, the farm now provides Tracklements with all of their yellow mustard seeds. "We make as good a product as we can all the time, so if we have an opportunity to make something better, to have someone grow something for us, we grab it and go for it." Guy recalls how "last year someone bashed on the back of the van and said, 'I've got a ton of quinces, can you do something with them?' and we said yes, we can. I love that."

The first thing that struck me was the similarity of the mustard plant, with its bright yellow flowers, to rape, that enemy of hayfever sufferers everywhere (however, it definitely doesn't have the same eye-watering properties). Another thing that surprised me was that the entire plant is edible. The leaves have a lovely peppery quality, rather like watercress or rocket (I was itching to steal a bundle and try them out in a pesto or salad). We were shown the little seed pods on the plant, shaped rather like tiny green chillies, and the tiny budding mustard seeds within. Eaten raw, they have a real kick to them.

The field was full of butterflies and bees, flitting amongst the mustard plants that, in some cases, were as tall as me (as you can see from the above photo of Guy and myself...though he is in no danger of being dwarfed by the mustard, as evident from the fact that he had to stoop substantially to be the same height as me). It was amazing to think that this, with very little processing involved, turns into one of the nation's favourite condiments (incidentally, Tracklements' top-selling products are plain wholegrain mustard, followed by horseradish and onion marmalade). Perhaps surprisingly, when BSE hit the UK, sales of Tracklements mustard went up. "I think more people were going back to their butchers, because they trusted the meat more, and that's where our products were being sold." The plain wholegrain is only the start of Tracklements' mustard selection, however: the range also includes Strong English, Beer, Green Peppercorn, Original Urchfont (with a hint of chilli), French Dijon, Spiced Honey, Horseradish, Organic Tarragon, Organic with Honey, and Lemon.

An artist's palette of different mustards.

After a delightful picnic in the mustard field, sitting on bales of hay, drinking cider and eating ham, cheese and pork pies (with lashings of different mustards, of course - my favourite was the spiced honey, followed closely by the lemon, which are both fantastic with pork and strong cheese), we headed to the Tracklements factory to see the production process in action. The air in the factory was heady with the scent of vinegar and spice; we were shown giant tubs of cardamom pods, dried chillies and peppercorns just waiting to go into the big blue grinder. We saw and felt newly-bottled jars, their contents still hot, and huge mixing pans that can hold enough ingredients for around 360 jars of product. We watched the jars being labelled and packed and examined the imposing-looking machinery (which actually turned out to be simple equipment like a dicer, or a mixing vat). We were dwarfed by absolutely enormous vats of vinegar (Tracklements use three different varieties, depending on the sauce), the scent of which pierced the air like a knife.

We watched Guy make a batch of mustard, throwing handfuls of spices into the grinder, as he informed us that there is no real written recipe; it's all done by feel. I was amazed that he seemed to be doing no measuring whatsoever, just throwing spices in by the bucketful, but I suppose if you've grown up in the business you've probably got it memorised by now. The smell from the grinding mustard and spices was amazing; we were able to taste the mustard seeds before and after being crushed, and notice their flavour intensifying. The advantage to grinding the spices minutes before processing them into Tracklements mustard is that all the essential oils are retained; it's the same reason why cookery writers will always advise you to buy whole spices and grind them yourself. Plus, you'd have to be a bit mad to forego the amazing smell of ground spices that emanated from the 25 year old grinder in the factory, still going strong.

We met Sam, the mustard maker, who showed us how the ground mustard seed and its accompanying spices are doused in vinegar in a large vat and then stirred every day with an enormous paddle to allow the spices to soak up the liquid and the flavours to develop (during busy periods Tracklements can make 30 barrels of mustard in a day). It wasn't particularly surprising to learn later that Sam is in fact a champion boxer - you need some pretty impressive arm muscle to stir mustard that has been thickening for a week (I should know - I tried it, pathetically prodding it with the plastic paddle and entirely unable to achieve so much as a full clockwise stir).

As Guy remarked, the Tracklements factory contains "everything you'd find in a home kitchen, only bigger" - choppers, grinders, pans, spoons. The raw materials are all natural, and the best Tracklements can find. "If I went to the cooks and put a big bag of garlic powder in their kitchen, five minutes later it would end up back on my desk. 'We don't want to use this', they'd say. I think that's really important." It's a far cry from the kind of factory where everything goes into a closed machine system and comes out processed to oblivion and ready for sale. Guy recalled a trip to a mustard factory in France, where he noticed a valve in one of the machines. Asked what it was for, the factory owner told him that he used it to alter the quantity of air in the mustard - if asked by a supermarket to produce the same sized jar of mustard for, say, one euro instead of four, he would just add more air to the existing mustard. I was slightly horrified by this.

Guy was keen to impress upon us the notion of a "happy food business". Tracklements, and the small delis they stock ("our bread and butter"), may be small businesses, but they are happy ones. "I love that," he said. "As you go further up the scale, moving up to places like Asda and Tesco, things probably aren't so happy there. We're trying to be as good and honest with good as we can be." He sees Tracklements as "not really reinventing, much more rescuing" sauces and condiments, often starting from a historical background to make a new product. Guy cites Tracklements' new fruit cheeses as an example of this approach. "I can find cheese recipes for every fruit that ever existed in old books. If you hadn't seen that before - for example, a gooseberry cheese spiced with nutmeg - you'd think it modern, but it's not. It's very, very ancient."

"We always say that 'you won't find a kumquat in the factory'. We try not to make things for effect, we try to make things with some sort of provenance. There's a reason those old recipes work - they would have been safe from a preserving point of view, as they were made to sit on the shelf for a year. We'll make six jars upstairs in the test kitchen, then multiply that by 30 or 40. We make a batch and off we go." Guy recalls a "fabulous lemon pickle from one of those old books. I thought, wow, that sounds really interesting. It involved chopping up lemons, salting them for 24 hours, washing the salt off, then adding mustard seed, spice, and horseradish. It was 250 years old, that recipe. I thought it was delicious." Unfortunately, the product didn't sell very well, which Guy thinks is "because it was called lemon pickle. We should have called it 'Uncle John's pickle' or something."

He recalls the time Tracklements took their products to the Italian market, the Slow Food festival in Turin. While attempting to sell very traditional British items to the Italians might seem difficult, Guy believes products like Tracklements' transcend cultural boundaries. "The thing to do is just let people taste it. They ask 'what does it go with?' and I tell them, 'whatever you want it to'." I am living testament to this: a huge fan of Tracklements Crabapple Jelly, I shun their recommendation to serve it with roast pork and instead have devoured mine plain on toast, with strong cheddars, game, and even with smoked mackerel.

(However, telling an Italian that Tracklements sauces go very well with "cane" did not go down too well - there is a very subtle distinction in pronunciation between the Italian words for meat, carne, and dog, cane). "They were a little bit horrified."

Top left - my own personal jar of Tracklements mustard, never to be opened, but savoured visually until I am old and grey.

I had a thoroughly enjoyable day at the mustard field and factory; I've never been to a food factory before and it was wonderful to see how a raw material is turned into the end product on the shop shelf. I'd always thought of factories as rather intimidating places, but the Tracklements factory was so small and intimate, and it was great to see no bizarre things being done to the food - as Guy said, it's basically your average home kitchen, but on a bigger scale. I have to admit that I never really ate mustard before this day, but now I'm a little bit of a convert, especially with all the exciting Tracklements varieties available, and especially because I was sent home with a bag groaning under the weight of six jars of mustard (one of which was specially customised with my name on the label, which sent me into something bordering on a paroxysm of joy - it's the small things in life).

New marketing campaign for Tracklements Spiced Honey mustard, I'm certain.

So eager was I, in fact, to start experimenting that I made this mustard-themed dish as soon as I got home. I very rarely see a recipe, think "yum", and am so keen that I end up cooking it that day, so this is testament to my excitement about all things mustard-related. It's based on one of the recipes in the Tracklements catalogue, for chicken stuffed with mustard and wrapped in bacon, but I adapted it a bit by using cream cheese instead of cheddar and mascarpone, and wrapping the chicken in Parma ham rather than bacon, because I love the wafer-thin saltiness it brings to a dish, particularly after crisping in the heat of the oven.

I also added some thyme to lift and freshen the flavours, and because its lovely jade green colour looked beautiful against the pink ham and pale chicken. The Tracklements recipe uses Original mustard, but I used the Spiced Honey variety, because I thought the sweetness would work very well with the salty ham. I baked my chicken on a bed of mushrooms, which ended up dark and caramelised, saturated in the salty juices from the chicken and the ham, with a hint of honeyed sweetness from the mustard. My boyfriend also heard 'mustard' and demanded mustard mash, so I served the whole thing on top of a big mound of gloriously fluffy, spiced mashed potato. We ate it outside in the glorious summer evening, with large glasses of white wine. An excellent end to a very interesting day.

Mustardy stuffed chicken wrapped in Parma ham on mustard mash (serves 2):

2 free-range chicken breasts
4 slices Parma ham
4-6 heaped tbsp garlic and herb cream cheese
2 tsp mustard (or more, depending on how much you like mustard)
A few sprigs thyme
2 large potatoes, cut into chunks and peeled if you like (I never bother)
Salt and pepper
Olive oil
Milk and butter
A packet of mushrooms, sliced
Green beans, to serve

First, pre-heat the oven to 180C. Bring a large pan of water to the boil.

Lay out two slices of Parma ham next to each other and slightly overlapping. Place the chicken breast in the middle. Make a slit through the chicken breast and open it out (but don't cut it in half). Mix the cream cheese with 1tsp of the mustard and some thyme leaves, and use half of this to stuff the chicken breast. Close it and wrap in the ham, then repeat with the other chicken breast.

Place the sliced mushrooms in an oven dish and drizzle with olive oil, salt and pepper. Place the wrapped chicken on top, scatter with thyme sprigs, and put it in the oven for 20-25 minutes, or until cooked through.

Meanwhile, boil the potatoes until tender, then mash with the salt, pepper, mustard, milk and butter to taste.

Serve the chicken and mushrooms on top of the mustardy mash with some steamed green beans alongside.

I'm quite the mustard convert now (as evident from the rather silly photo above), and can't wait to try it out in other recipes. I'd like to thank Tracklements, particularly Guy and Becky, for a really fantastic day out, and Emma at Wild Card for inviting me.