Rinse 200g of dry red kidney beans thoroughly, then soak them in 4 cups of water overnight. You will see that the beans double in size and become smooth and wrinkle-free. This ensures even cooking and prevents tough centers.
Drain the soaking water. Transfer the beans to a pot or pressure cooker with 4 cups of fresh water, a bay leaf, and 1 tsp of salt. Cook until completely soft. Test by pressing a bean between your fingers—it should mash instantly with zero resistance. Do not discard the cooking water!
Heat 3 tbsp of ghee or oil in a heavy-bottomed pan. Add cumin seeds and let them sizzle. Stir in the finely chopped onions and cook slowly over medium heat. Sauté until they turn a deep, rich amber-brown. This deep caramelization is key to a rich, dark gravy flavor.
Add 1 tbsp of ginger-garlic paste and 2 slit green chilies to the caramelized onions. Sauté for 1-2 minutes. Cook until the raw, sharp aroma of the garlic disappears, replaced by a warm, sweet fragrance.
Pour in the pureed tomatoes, followed by turmeric, Kashmiri chili powder, coriander powder, and cumin powder. Cook this masala over medium-low heat. You will see the moisture evaporate and tiny droplets of oil begin separating at the edges of the pan, indicating the spices are perfectly roasted.
Add the boiled kidney beans along with all of their starchy cooking water to the masala. Stir well to combine. Bring the curry to a boil, then cover and simmer on low heat for 15-20 minutes. This allows the beans to absorb all the delicious spices.
Use the back of your spoon to mash a small handful of beans against the side of the pot. Stir in garam masala and crushed kasuri methi. You will see the gravy instantly turn thick, creamy, and cohesive. Garnish with fresh coriander and serve hot.