Asafoetida (a.k.a. hing) is known for the intensity of its aroma when raw. Its name is Latin for “stinking gum” because of its strong, sulfurous smell. Once cooked, that smell softens considerably and the spice becomes an excellent background for other flavors. It is a staple of Indian cuisine and perfectly complements other spices common in Indian dishes like cumin and ginger. If you want to make a dish with authentic South Indian flavors, you will need what asafoetida provides. While it is the best way to get these flavors, it is not the only way as there are several effective asafoetida substitutes.
Your best bet: Onion and garlic powder
Because you are replacing a powder with other powders, this asafoetida substitute will not have a significant effect on the texture of your dish.
A decent second choice: Leeks and fresh garlic
Leeks and garlic are another good way to provide a flavor similar to that of asafoetida. Leeks look like oversized scallions and are in the allium family along with onions and chives. Leeks can bring a milder onion flavor to your dish while fresh garlic provides pungency. Together, they provide an effective substitute for asafoetida.
To bring out the flavors of leeks and garlic, saute them in ghee or vegetable oil before adding them to your dish. Try small amounts of a 50/50 mix and adjust to taste.
When using this alternative, bear in mind that leeks are extremely fibrous and will add a lot of bulk to your dish. This might not be a bad thing for some dishes, but can make a big difference in a dish that is supposed to have a smooth texture. You can minimize this issue by blending or grating your garlic and leeks.
In a pinch: Shallots
Like leeks, shallots provide a flavor that is milder than that of onions. Along with the onion flavor, there is a hint of garlic that allows asafoetida to be a flavorful substitute for the onion and garlic combination. With this one herb, you can add the two main flavor notes of asafoetida to your dish. Use shallots in much the same way that you use leeks and garlic: chop and fry them in ghee or vegetable oil to release the flavor.
Chives are another relative of the onion; they look like a cross between narrow scallions and blades of grass. There are many different varieties of chives including one type called garlic chives. As you may have guessed, it has a garlic flavor to complement its mild onion-like flavor. Garlic chives are an excellent substitute for asafoetida.
Simply combining fresh garlic and fresh onion can also provide much of the flavor that would get from asafoetida. You will need to use this alternative in a dish where the fibrous bulk will not be an issue or you can opt to blend or grate them.