Cook the lentils in the water with salt, turmeric and cayenne pepper for approx. 15 minutes until soft (caution: likes to burn, so stir again and again!). Drain the lentils in a colander.
Fry the onion in a little oil, then add the garlic and ginger puree and fry with it. Add tomatoes, lentils, garam masala, crème fraîche (or yoghurt) and coriander and heat everything again.
The lentils are really spicy. If you don`t like it so spicy, you should use a little less cayenne pepper or a little more crème fraîche.