A common technique in South Asian and Indian cuisines, blooming spices helps you get the most out of their flavor. It’s basically just a process that involves cooking the spices in hot oil or clarified butter (ghee) until they’re fragrant, but not brown. You can think of it like sauteeing onions and garlic before adding in your other ingredients. It basically just helps you start off your dish with a flavorful base.
You may have heard this process called chhonk, tadka, vaghar, or tempering—depending on where you heard about it. It works because most flavor compounds in spices are fat-soluble and fat coats your tongue, so blooming spices in fat lets those flavors stay in contact with your taste buds for longer.
Blooming spices is simple. Just heat a couple tablespoons of oil or ghee over medium-low heat. Add ground or whole spices as well as other aromatics (garlic, bay leaves, etc.). Cook until you can smell it, which should only take a couple of minutes. And there you go! From there, you can make your lentils, vegetables, or sauce all the more flavorful.