Red Lentil Dal with Cumin and Turmeric

Rinse 1 cup red lentils in a fine mesh strainer under cold water until the water runs mostly clear; this removes excess starch that would make the dal gluey.
In a medium pot, combine the rinsed lentils, 3 cups water, 1/2 tsp of the salt, and the turmeric. Bring to a boil over high heat, uncovered.
Once boiling, reduce heat to low so the pot barely simmers, skim off any foam with a spoon, and cook uncovered for 18-20 minutes, stirring occasionally, until the lentils fall apart and look like a thick, smooth porridge with no distinct grains left.
While the lentils simmer, heat 2 tbsp oil in a small skillet over medium heat until it shimmers.
Add the cumin seeds and cook for 20-30 seconds, just until they sizzle and smell toasty; do not let them turn dark brown or they will taste burnt.
Add the diced onion to the skillet and cook, stirring often, for 5-6 minutes until soft and light golden at the edges.
Stir in the garlic and ginger and cook for 30 seconds until fragrant, then add the diced tomato, coriander, cayenne if using, and the remaining 1/2 tsp salt.
Cook the tomato mixture for 3-4 minutes, mashing the tomato slightly with the spoon, until it softens into a thick paste and the oil starts to separate at the edges.
Scrape the entire onion-tomato mixture into the pot of cooked lentils and stir well to combine.
Simmer the dal uncovered for another 3-5 minutes over low heat to let the flavors meld; if it looks too thick, stir in a splash of water until it reaches a soft, pourable consistency.
Taste and adjust salt as needed, then stir in the lemon juice.
Ladle into bowls, scatter fresh cilantro on top, and serve hot with steamed rice or warm flatbread.

Rinsing the lentils well before cooking prevents a gluey texture and gives a smoother, silkier dal.

The tempered onion-spice mixture (called a tadka) should be added at the very end so the spices stay vibrant instead of turning bitter from overcooking.