Cook the Dal:

In a large pot, combine the masoor dal, water, turmeric powder, and salt. Bring to a boil, then reduce the heat to low, cover, and simmer until the dal is tender and broken down, about 20-25 minutes. Stir occasionally to prevent sticking. Add more water if needed to reach your desired consistency.

Prepare the Tadka:

In a separate small pan, heat the ghee or oil over medium heat. Add the cumin seeds and mustard seeds (if using) and let them crackle.
Add the chopped onion, garlic, ginger, and green chilies. Sauté until the onions are golden brown.
Stir in the chopped tomato, red chili powder, and garam masala. Cook until the tomatoes are soft and the oil starts to separate from the mixture.

Combine Dal and Tadka:

Pour the tadka over the cooked dal and mix well. Simmer the dal for an additional 5 minutes to infuse the flavors.

Garnish and Serve:

Garnish with fresh coriander leaves. Serve hot with steamed rice or Indian bread like roti or naan.