Soak the lentils in water for at the least 5 h. Shorter soaking time causes cooking time to go up. Overnight soaking is also fine
Weigh all the spices and grind the cardomom seeds (after peeling them first). Place the mustard seeds, the cumin seeds and the cinnamon stick together
Place the ground cardomom and turmeric together
Grate the ginger, and mince the garlic and keep them together
Take the seeds out from the red peppers and finely slice the peppers
Boil hot water, place the tomatoes in a bowl and pour the hot water over them. After 2 minutes replace by cold water. After a while peel and then cut the tomatoes
Dice the onion
Place the soaked lentils in a pan with some water. Add the salt. Bring them to a boil and cook them for 20-30 min
Place the oil in another pan and heat up with medium fire
Add the mustard and cumin seeds and cinnamon stick and wait until the musterd seeds start to pop (1-2 minutes)
Then add the chilli peppers, the onion, the ginger and the garlic and cook for about 10 min, until the onions are tender. First high fire, later at low fire
Add the ground turmeric and cardomom seeds and the diced tomato. Wait until the tomato falls apart (5 min). Take the cinnamon stick out and discard
Check the lentils for done-ness. if there is surplus water, remove this with a siff. Add the lentils to the pan with the spices and cooked vegetables and stir. A thick slightly fluid appearance is what you should aim for
Just before serving, add the cream or crème fraiche to the dish and garnish with coriander leaves or offer the latter separately.