Via Ruth DeSouza
Bring the tomatoes, lentils, salt and 900ml of water to a boil in a medium saucepan, skimming and discarding any white foam that rises to the surface. Reduce the heat and simmer for 20-25 minutes, until the lentils are very soft but still hold their shape.
Meanwhile, blitz the chilli powder, turmeric, lime juice, ginger and sugar in a food processor until smooth, or chop together on a board. Once the lentils are cooked, stir in the seasoning mix and simmer for another five minutes, so the lentils absorb all the flavours. Take off the heat and blend with a stick blender to a thin, soup-type dal about the consistency of double cream.
Just before serving, heat the ghee in a small, heavy-based frying pan over a medium-high heat. Once the fat is hot, add the curry leaves, chillies, mustard seeds, fenugreek and garlic, one at a time, pausing for a second between each addition and swirling the pan. Cook for about 30 seconds, until the spices are toasted, the curry leaves sizzle and pop, and the garlic begins to brown at the edges.
Spoon the spices over the dal and serve immediately with basmati rice and the green chutney (see opposite).
