Put on your kettle to boil. Add the onion, garlic and ginger to a saucepan along with the cumin seeds, oil and chopped tomatoes. Fry over a medium heat for 3 minutes before adding the tandoori spice and about 100ml water. Stir together for 2 minutes to release the flavours from the spices.
Crumble in the stock cube, add the lentils and pour in 625ml boiling wat