For the curried lentils with fried egg, peel and finely chop the onion. Wash tomatoes, remove stalk and cut into cubes.
Melt clarified butter in a pan and fry onion in it. Add tomatoes, curry and pour some cooking water (alternatively vegetable soup) and let it simmer a bit, so that a creamy sauce is formed.
Add the cooked lentils and continue cooking briefly. If the sauce is not thick enough, mash some of the lentils so that they thicken. Fry fried eggs in the pan and serve with the curried lentils.