The keen cook will always have a "must-try" list of ingredients that they keep tucked away in their head somewhere. This list is likely to be subdivided into "easily accessible ingredients that I see all the time but just haven't got round to experimenting with yet" and, the more interesting list, "ingredients that I read about every now and then but can't for the life of me find in any of the grocery stores or supermarkets I've ever visited". The latter list pretty much reads like your average Yotam Ottolenghi recipe: kashkaval cheese, okra, shiso leaf, dried barberries, fennel pollen, pandan leaf. It's apparently become the done thing, now, to read his recipes on the Guardian website every Saturday and leave bitchy comments along the lines of "oh good, a recipe with twenty ingredients, none of which I can source in my local corner shop". The Guardian has neatly organised Yotam's recipes into a handy list from which you can judge their exoticism and complexity in an instant - not from the title, but from the amount of comments posted below each recipe. My favourite one was a comment on one of Ottlenghi's recent recipes for a soup with halloumi croutons:

“I find articles like this hugely irritating and presumptuos [sic]. Admiitedly [sic] I may,in my irritation have missed an explanation . If so I apologise but as a first point what on earth is halloumi? I know I could look it up but why should I? A recipe should explain things and it is presumptious [sic] to assume that we are all conversant with the ingredients of all cuisines.”

The fact that said comment was posted by someone with the username "hugelyirritated" only adds to the fun. I just love their idea that all recipes should only contain ingredients one is familiar with. Is the point of a recipe not to suggest new and exciting ideas in cooking, perhaps using new and exciting ingredients? Apparently not. Maybe "hugelyirritated" would like a recipe book consisting solely of instructions on how to make boiled eggs and toast.

I was also slightly astounded that an ingredient like halloumi could cause such controversy. How can anyone not know what halloumi is? (I ask with trepidation - surely it's only a matter of time now before "hugelyirritated" tracks me down and leaves a similar comment on this blog. If so, he/she might first like to have a look at my rant about bad grammar and spelling a couple of posts back).

I love Yotam Ottolenghi's recipes. I like that he introduces me to weird and wonderful ingredients along with new ways of cooking those things I'm already familiar with (aubergines, for example, or cauliflower - hopefully "hugelyirritated" doesn't need an explanation for those). He is almost wholly responsible for replenishing my "must-try" list of obscure ingredients, ensuring there's always something new I'd like to try in the kitchen, that I never become complacent with my cooking. Although I do admit that his inclusion of fennel pollen in one of his recent recipes made me a little exasperated. Yotam, my dear, I will normally be straight to your defence on the Guardian front line, but even I had to admit that this may have been pushing it a little too far. Very few cooks, very few keen cooks, (i.e. those that are "conversant" with the notion of halloumi), are going to go to the effort of ordering fennel pollen online.

How times have changed since I first gained an interest in food. Whereas now my "must-try" list is bursting with obscure middle-Eastern berries and vegetables, exotic Thai herbs, cheeses whose names I can't pronounce and fifteen types of mustard seed, for quite a while in the early days the most elusive ingredient on said list was orange flower water.

I seemed to read about it constantly. I remember Waitrose brought out a recipe book featuring an orange flower panna cotta. Nigel Slater spoke eloquently on the subject in his Real Good Food. Nigella suggested scattering a few drops of the stuff over a plate of baked figs. Ideas of this fragrant elixir wafted tantalisingly around my head; I had no idea what it would smell or taste like (our English climes don't really facilitate the blossoming of orange trees), but I was frequently assured by cookbooks that it would add a certain je ne sais quoi to everything I added it to. Too much, though (I was warned), and my food would taste like soap.

It wasn't until a trip to Morocco that I got my hands on the stuff (which I realise is a long way to go for an ingredient that you can now find in most supermarkets, but at the time I never took the initiative to do so - to this day I am unsure why).

I had stumbled across a shop that rather defies description; it seemed to be a pharmacy, an artist's supplier, a household store and a beautician all rolled into one. Huge tureens of powdered dye in all imaginable bright colours moulded into giant spiked cones lined one of the walls; big vats of loose spices and herbs stood in the middle of the floor; another wall was lined with mysterious looking bottles and bags. The owner took great delight in detailing all his wares to us, but it was the orange flower water that caught my cook's eye. This fragrant stuff of my dreams came not, as perhaps might have been fitting for something so exotic and wonderful, in a delicate glass vial adorned with a golden orange-shaped stopper. Rather, it came in a neon green plastic bottle with a garish Arabic label on the front bearing a picture of an orange tree. Still, I cherished it, tenderly encasing it in bundles of my clothes to ensure its safe passage back to England in my suitcase (even though it was a plastic bottle, so this was entirely unnecessary). Every time I scattered a few drops of that precious liquid from its green bottle, I remembered that weird and wonderful Moroccan shop.

I also remember the first time that elusive orange flower scent reached my nostrils. We'd taken a trip to the El Badi (meaning "incomparable palace") ruins, the remnants of a magnificent palace built in 1578 by king Ahmad al-Mansur. The original building is thought to have consisted of 360 rooms, an enormous courtyard, and a 90m long pool. It was apparently lavishly decorated with Italian marble and gold from Sudan, in its heyday. Unfortunately it was later torn apart and used to decorate another Sultan's palace, hence the ruins. I was completely captivated by what remained, which is unusual for me. I think it's because, shamefully, I was imagining the palace, in all its glory, to have looked exactly like the Sultan's palace in Aladdin (my all-time favourite film and the underlying reason for my love of all things Middle Eastern...although I try not to admit that too often).

The ruins were overgrown in places with orange trees. This also captivated my attention, simply because until then I'd never seen a real, growing orange tree in its natural habitat. What was most remarkable, however, was the scent. The oranges were blossoming, and the air was thick with the perfume of their flowers. It was completely new to me, and wonderful. It's hard to describe the scent of an orange flower; there's an underlying floral, perfumed note, with the tang of citrus cutting through it. I remember walking around and sticking my nose amidst the flowers, wondering if it would be worth stealing a bit of blossom to carry around with me (I didn't, remembering I am a Responsible Traveller).

I'd like to say something rather clichéd along the lines of "I am transported back to those orange groves every time I use orange flower water in my cooking..." but if truth be told I've now gone through so many bottles of orange flower water, purchased from various Middle Eastern or Indian supermarkets, that I don't tend to go in for Proustian recollections, instead just savouring the mysterious aromatics of that distilled liquid as I drizzle a little over a cake or some couscous.

I admit that it was hard to say goodbye to the original green plastic bottle; I was deeply upset when it finally ran out, believing that no orange flower product I could purchase in the UK would be anywhere near as good as that acquired just a kilometre or so from those lovely orange flowers themselves. I was, of course, wrong, especially as the brand I buy (Cortas) is a Middle Eastern one, so likely to be just as authentic.

This recipe is a celebration of the humble orange, both in flesh and in flower. It's an absolutely incredible cake, with a really pronounced flavour both of oranges and their blossom. There's just enough orange flower in there to lend an intriguing perfumed note, without being too overpowering. The cake itself is gluten free, made with polenta and ground almonds and pistachios (for no particular reason, but I think it's good to have a gluten-free cake in your baking repertoire). I love the resulting texture; very slightly grainy, but soaked through with a sweet, sticky syrup after baking to lend a wonderful moisture. The pistachios are less finely ground than the almonds, so you have a lovely crunch from the pieces of nut too.

It's hard to describe the flavour of this cake. There's a sharp citrus tang from the use of orange, but that's somehow mellowed by the flower water. I've given it to a few people to sample, and the results have been very positive. I think the orange flower is the key here, because it gives it a whole new level of flavour that's hard to pin down but incredibly moreish.

Pistachios, almonds, pomegranate, and orange flower - favoured ingredients in so much Middle Eastern and North African cooking, and some of my favourite to cook with. I used whole pistachios as well as pre-ground almonds, and just ground them in a blender. We've lost the plastic lid that goes over the funnel of the blender while it's working, meaning you have to hold your hand over it so bits of pistachio don't fly out. Instead I stuck my nose in there and inhaled the deeply delicious scent of fragmented pistachios; warm, toasty, nutty, slightly sweet.

The cake recipe itself is incredibly simple - everything just gets mixed together in a bowl and then baked. The genius lies in the sticky, orange flower-scented syrup that soaks the cake as it's still hot from the oven. Rather like a lemon drizzle cake, but with an exotic floral twist. I scattered some pomegranate seeds over the finished product which look beautiful and add another layer of texture. This is a great cake for transporting, too, as you can cut it into squares like a brownie. It also means you feel a bit less guilty when coming back for a second piece. Or a third.

This cake actually reminds me a bit of baklava. Obviously it is totally different, as there's no pastry involved, but the grainy crunch of nuts infused with sugar syrup and flower water is a feature both desserts share. I honestly can't get enough of it. It's really light, as well, from the citrus and the flower water and - I think - the lack of flour. It has an almost mousse-like texture.

Light as a cloud and fragrant as a flower. If you only make one cake from my blog, I think it should probably be this one.

Orange flower, pistachio and almond polenta cake (makes 20 squares):

180g butter, softened
180g caster sugar
3 eggs
150g polenta
50g ground almonds
50g ground pistachios (buy shelled ones and just pulse in a blender until finely ground)
1 tsp orange flower water
2 tsp baking powder (use a gluten free version to make this cake totally gluten free)
Zest of an orange
Seeds from half a pomegranate

For the syrup:

50g caster sugar
1/2 tsp orange flower water
Juice of an orange

Pre-heat the oven to 180C (165C fan). Line a shallow brownie tin or traybake tin with baking parchment (mine was about 15x25cm).

Beat the butter and sugar together with an electric mixer until pale and creamy. Beat in the eggs one at a a time. Add the polenta and nuts along with the orange flower water, baking powder and orange zest, and beat until thoroughly combined.

Pour into the prepared tin and bake for 35 minutes.

Just before the cake is ready, make the syrup. Bring the orange juice, sugar and orange flower water to the boil in a small saucepan and simmer for a couple of minutes until thick and syrupy.

Remove the cake from the oven. Use a skewer or fork to pierce holes all over the surface of the cake (try not to pierce it all the way through). Pour the syrup evenly over the cake and scatter with the pomegranate seeds. Leave to cool. When cool, dust with icing sugar and cut into squares to serve.