What's a spice that changed your cooking?
It wasn't so much the ingredient itself that changed the way I cooked. Instead, it was the realisation that there is so much potential variety between seemingly very similar items. Black pepper is a fantastic spice, but I found Tellicherry pepper to be a deeper, more fragrant flavour, and the difference was far more than I could have imagined at the time.
It changed the way I viewed cooking. Fresh herbs compared to dry. Smoked spices compared to standard. Home-made pastes compared to store-brought. Quality of products started to matter. Gone now are the days of using "balsamic vinegar" the consistency of water to dress a salad. The differences between vegetable oil and olive oil suddenly mattered, and with it came the need to know those differences. That opened me up to deeper knowledge about the cooking process. Smoke points of oils, the Maillard reaction, the difference between roasting and braising.
I always enjoyed cooking, and I could make some pretty decent dishes before that revelation, but I think it was a real turning point.
My mum had a recipe for using up cold roast lamb, which involved carving it into smallish slices, frying it with onions and green beans and mixing it with cooked rice so as to make a pilaf. (Not a risotto. It should be fairly dry, not oozy.) I adapted this by adding pine nuts, chopped parsley and torn-up mint and a good squeeze of lemon, but it was still missing something.
I was reading about Arabic food and I came across Baharat, which is really just Arabic for ‘spices'. The blend I use is a mixture of paprika, black pepper, coriander seed, cumin, cinnamon, cayenne pepper, nutmeg, cloves and cardamom, all ground up and sold in a tin. I suppose I could make my own, but I don't.
Anyway, shake a good spoonful of this stuff over your lamb pilaf and you're halfway to the Levant on a carpet of deliciousness. I've since used it with lemon juice and oil to marinade chicken thighs, and my homemade version of the Israeli street food Jerusalem Mix (heavily-spiced bits of chicken, preferably including some of their internal organs, fried in a little oil and served in a pitta bread with salad and amba) also contains it as a primary spice, in the interests of Middle Eastern cooperation.
Some people use generic curry powder. I use generic Arabic spice mixture.
Different things have changed my cooking at different times.
Cilantro - leaves and roots.
Salt, once I really got its value in flavouring. This was maybe looking back the single most important discovery.
Celery used as a spice.
Thai bird chilies.
Fresh lemon and lime juice rather than the yellow and green plastic bottles.
(Can you tell I'm a fan of East Asian food? ;))
Believe it or not, salt. Yes, I know salt isn't a spice; it's a mineral. But I grew up in a household where we didn't eat much salt. As a result, I didn't use a lot of it in my cooking when I was on my own. Culinary school taught me that salt is my friend. OMG what a difference it made.
For me, it was Garam masala - Wikipedia
Look for it in the bulk spices section at your specialty foods store.