If you’re a fan of sushi and sashimi, then you’re already familiar with wasabi. For the uninitiated, wasabi is the tingling-hot, sinus-clearing pasty green condiment that accompanies those popular Japanese seafood dishes. In addition to serving it with sushi, we also like to add it to mashed potatoes and to mayonnaise, as in the recipe for Grilled Salmon with Wasabi-Ginger Mayonnaise.
Also known as Japanese horseradish, wasabi is a member of the mustard family. Fresh wasabi is expensive and hard to find, but you can get it in powdered or paste form at Asian markets and in the Asian section of the supermarket or an online source like Asianfoodgrocer.com. Powdered wasabi is the better option: It has more of a kick than the commercial paste, which is primarily available as a convenience. Buy wasabi in the smallest quantity available because, like dried spices, its potency dissipates over time.