Ingredients
250g/9oz/1¼ cups red lentils
¼tsp ground turmeric
2 tbsp mustard or any other vegetable oil
½ tsp brown mustard seeds
½ tsp panch phoran
4 hot dried red chillies
1 bay leaf
1¼-1½ tsp salt
2 tbsp thick tamarind paste or to taste
1 tbsp sugar or to taste

Method
1. Wash the lentils in several changes of water until the water runs clear. Put them in a medium-sized pan with the turmeric and mix. Cover with 1l/1¾pt/4½ cups water. Bring the lentils to the boil over a medium-high heat. Reduce the heat to low, cover partially and simmer for 40 minutes or until the lentils are tender. Stir now and then during the last 10 minutes. When the lentils are cooked, mash with a spoon to a pulp-like consistency.
2. Heat the oil in a large, wide, preferably non-stick pan or wok over a medium-high heat. When hot, add the mustard seeds. As soon as they pop, a matter of seconds, add the panch phoran, chillies and a bay leaf. Stir and fry for 5-6 seconds or until the chillies darken in colour. Add the cooked lentils, 150ml/5fl oz water and the salt. Stir to mix. Add the tamarind paste, a little at a time to get the sourness you desire. Add just enough sugar to balance the sourness. Bring to the boil. Turn the heat to low and simmer for 8-10 minutes. The finished dal should have the consisitency of a thick purée.