Some spices are statement flavors that speak for themselves. They're the big-name headliners that sell recipes the way A-list actors sell movie tickets. They may be subtle and unassuming like basil and sage or bold and brash like cumin and pimentón. They're the first name on the ticket, generally well-liked. Friendly, even. They play well with all sorts of flavors and ingredients, crossing culinary boundaries while always remaining the star.
Asafoetida is not that kind of spice.
To the uninitiated, its flavor and aroma can be downright alarming. Its origins and processing—it's the dried and powdered resin from a tree—make it one of those ingredients, like cheese, that make you wonder how we ever turned it into food. Historically it's been used as a medicine for all sorts of ailments—sometimes a promising sign for an ingredient, but always a weird one. Unlike many Eastern spices that have worked their way into Western cuisines, asafoetida (often called hing) has stayed mostly confined to its roots. Westerners from France to Turkey have coined all sorts of unpleasant names for it, of which devil's sweat is one of the more polite.
But oh what a wonderful substance it is! Asafoetida is one of the most distinctive spices in South Indian cuisine that transforms a dish (and the kitchen, and maybe the room adjacent to it) into something magical. It's one of the most interesting and memorable aromas you encounter when entering a South Indian restaurant or kitchen. When used judiciously the effect is nothing short of transporting; your forays into Indian cooking will benefit immeasurably from its use, for which there's no substitute.
What Does It Taste Like?
It's not as strange as it's made out to be. You can think of it like Parmesan, meaty collagen, or soy sauce: It gives dishes a super-savory element otherwise lacking in South Indian fare, which is almost exclusively vegetarian. And since it's always cooked in fat first, it yields a full, smooth, and satisfying mouthfeel that you may not be able to pin down but would miss if it wasn't there. A long list of obscure spices in an Indian recipe can be discouraging, but this one is definitely worth seeking out. This isn't an A-list spice, but it's one of the world's best supporting stars.
While the aroma of raw asafoetida isn't exactly what I'd call pleasant, everything changes when it's introduced to hot oil or butter. Usually one of the first aromatics added to a dish, its initial pungent and camphorous funk mellows out and is replaced by musky aromas that evoke a sense of place—a South Indian village—more than any comparable flavors. It's hard to describe asafoetida, but you know it when you smell it, and if you're a fan of this style of cooking it'll be right up your alley.
Asafoetida is mostly sold pre-ground and is available at any Indian grocery. You won't need any more than the smallest of containers because a pinch or two per dish is sufficient. Keep it very well sealed unless you want your whole cabinet to smell like it.
How to Use Asafoetida
Asafoetida isn't a spice to use in everything, but that doesn't mean it isn't a good everyday spice. It compliments most commonly-used Indian vegetables: potatoes, onions, cauliflower, peas, and quick-cooking greens. Whether making a more involved vegetable curry or a simpler sauté a pinch or two (or if your container is like the one above, just a squeeze from the top) added at the beginning will go a long way. It's also a common element of tarkas, the flavored fats made and poured on dishes right before serving. Either way, once your oil or butter (preferably clarified) gets hot, add your asafoetida and let it incorporate for about 15 seconds before adding other spices and aromatics. Your nose will tell you when it's ready.
Asafoetida is best used as a background note for other complimentary spices, like cumin, mustard seeds, dried chiles, curry leaves, ginger, and garlic. Add any combination of these things to your tarka to drizzle over beans, stewed vegetables, or anything at all. Or start your dish with asafoetida. As a dish cooks the asafoetida graciously recedes into the background, though while it lets other flavors develop it never disappears. The end result is an intensely aromatic dish with layers of flavor and a full mouthfeel. Consistently getting those layers and that texture seem like a challenge for many home cooks, myself included. With asafoetida that's just a pinch away.