Step 1

Combine the lentils and water in a large pot. Bring to a boil, then turn the heat down to simmer. Skim off any foam that collects on top. Cook, partially covered, until the lentils are tender, usually 15-20 minutes.

Step 2

While the lentils are cooking, make the tadka. Heat a skillet over medium heat and add the oil and onion, garlic, ginger, chiles, and a pinch of salt. Fry until soft, about 5 minutes.

Step 3

Add the spices: curry powder, mustard, coriander, and cumin, along with the salt. Stir to combine and cook for about 60 seconds, then add the tomatoes. Cook about 7 minutes to cook down the tomatoes if canned, or until the tomatoes are soft and saucy if fresh.

Step 4

Add the tadka to the cooked lentils, and simmer over low heat for about 5 minutes to infuse with flavor.

Step 5

Serve garnished with cilantro and with basmati rice.