Drain the soaked lentils and place them in a pan. Fill the pan with water to cover the lentils. Cook until tender, for about 40 minutes, on high heat. Once done, drain any excess water and set aside.
In a separate pan, melt the better over medium heat. Add the onions and fenugreek seeds, cardamom, garam masala and turmeric. Fry for about half a minute then add the onions and garlic paste. Sautee for about a minute. Add the tomato paste, curry paste and coconut milk, cook on low heat for 1 minute. If it starts sticking to the pan, stir in a bit of water.
Add the lentils, sprinkle salt and pepper and stir. Let it simmer for a 15-20 minutes over medium heat. The longer you let it cook, the more flavorful the dish gets. Once cooked, garnish with coriander leaves and sprinkle.