What's your favorite new ingredient?
I love this vegetable I discovered in Singapore and now get in Chinatown. It's a little bitter like brussels sprouts, and has the same juiciness as bok choy. We prepare it the same way you might bok choy—we cook it with salt and a little bit of chile and serve it as a side dish.
I'm also excited about spices. I went to Zanzibar a year ago and saw so many new spices and learned how to preserve and mix them. For example, sumac is not a new spice; it's been around forever. But I mix sumac with berbere (an Ethiopian spice) to get a wonderful blend.
What's the most versatile spice?
I don't look at spices like that. I think that if you grind your spices and keep them in small batches, you can use them in endless ways. The key thing is to have a spice mill or a coffee grinder, and to keep your spices cold and in tightly lidded boxes.