Heat the oil in a vessel and fry the onions for a little time.
.Add the crushed garlic and chilli powder. Fry again until it releases a nice aroma.
.Add 2½ cups of water, the tomatoes and the washed masoor dal and cook in a pressure cooker.
.When cooked, pass the mixture through a sieve.
.Boil for 15 minutes. Add salt.
.Serve hot with cooked rice and slices of lemon