In a large fine-mesh strainer, rinse the lentils under running water until the water runs clear. Drain the lentils and set aside until ready to use.
Heat the oil in a medium saucepan over medium-high. Add the onion and cook until soft and golden, about 5 minutes.
Stir in the garlic and ginger and cook until fragrant, about 1 minute.
Stir in the coriander and turmeric and cook until fragrant, a few seconds more, then stir in the reserved lentils to coat.
Add 4 cups of water and bring to a boil. Reduce the heat to maintain a simmer and cook, stirring occasionally, until the lentils have broken apart and the texture is almost creamy, about 30 minutes.
Remove from the heat and stir in the lemon juice, salt, and garam masala.
Heat 2 tablespoons of ghee in a small skillet over medium-high. Add 1 cumin seed into the pan. When the seed sizzles, add in the rest of the cumin seeds and the asafoetida.
Once the seeds are sizzling, add in the dried chile, then stir in the Kashmiri chili powder or paprika, if using.
Immediately pour the mixture over the dal. To get all of the flavored ghee, put a spoonful of the dal into the skillet, stir, and spoon it back into the rest of the dish.
Garnish with cilantro leaves and serve with basmati rice, achaar, yogurt, and papad or potato chips, if desired.
