Wash 175g of small red lentils in cold running water. Put 1 tsp of cumin seeds in a spice grinder. Crack 8 cardamom pods, extract the black seeds from within and add them to the cumin. Grind the spices to a coarse powder. (You can also do this with a pestle and mortar.) Tip the ground spices into a food processor, then add 35g of ginger, peeled and cut into pieces, 3 cloves of garlic, peeled, 1 tsp of turmeric powder and 2 small chillies. Pour in 1 tbsp of groundnut oil and process to a coarse paste.

Pour 2 tbsp of oil into a deep saucepan over a moderate heat, add 1 tsp of yellow mustard seeds and let them cook for a minute, Stir in the spice paste and fry for a minute or two until fragrant. Stir in 1 tbsp of tomato purée. Chop 250g of tomatoes and add to the pan, continue cooking for a few minutes then, as the tomatoes soften and collapse, add the lentils, drained of their water, 3 tsp of tamarind paste, 750ml of water and a ½ tsp of salt. Lower the heat and leave to simmer for 25 minutes. Enough for 4