Heat ghee in a kadhai or heavy-duty casserole. Add cumin, and saute for 10 – 20 seconds. Add finely chopped onion and fry till onion turn light golden.
Once the onion is nicely fried, add ginger and garlic paste, chopped tomato, salt, turmeric, chilli powder, and coriander powder. Fry for 5 – 6 minutes over low heat. The oil should start separating from the masala, and the tomatoes break down completely.
Add tomato paste or ketchup and pressure-cooked dal. Stir to combine. At this stage, if you feel the dal is way too thick, get desired consistency by adding the remaining 2 cups of water, as after simmering, it tends to become thicker.
Add cream, Garam Masala powder, kasuri methi, sliced green chillies, julienned ginger, and fresh coriander. Mix nicely. Taste, and if required, add more salt and seasoning.
Now allow the dal to simmer over low heat, stirring at regular intervals for 10 – 15 minutes. This step gives a deep, slow-cooked-like flavour to the dal.
Transfer the Dal Makhani to a serving bowl. Garnish with fresh coriander leaves and cream (optional). You can use ginger and green chilli slices as well for garnishing. Add a dollop of butter on top before serving.
Serve Dal Makhani warm with Naan.