Wash and simmer the red lentils in plenty of water until they soften into a thick puree, skimming off any foam as they cook.

Toast the fenugreek, coriander, and cumin seeds in a pan until fragrant, then grind them into a coarse paste using a mortar and pestle.

In a wide pan, fry mustard seeds and curry leaves until they crackle, then cook the shallots until golden before steaming the squash cubes in the pan for several minutes.

Add the eggplant cubes and a little water, followed by the tomatoes and ground spices, salt, sugar, tamarind, and chile, simmering until the tomatoes break down and the squash is tender.

Merge the lentils and vegetables together, stir in the green beans, and add enough water to reach a soupy consistency, simmering for a final few minutes to finish.