Rinse the lentils well in a sieve under running cold water. Place in a heavy-bottomed saucepan with 1 1/2 pints (900 ml) cold water and bring slowly to the boil, skimming off any scum that rises to the surface.

Reduce the heat to very low, cover, leaving a gap for the steam to escape, and simmer gently for 1 hour.

Pick over the spinach, trimming it and removing any large tough stalks (these can be used in soups and other dishes); only the leaves and tender stalks are used for this recipe. Wash very thoroughly in several changes of cold water; drain.

Heat the ghee in a large, heavy-bottomed flameproof casserole dish and stir-fry the ginger and chilli pepper briefly over a moderately low heat; stir in the coriander and add the spinach. Continue stirring until the spinach has wilted.

Add the lentils, together with their cooking water, scant 1 tsp salt, some freshly ground black pepper and stir once more. Cover tightly and reduce the heat to very low; simmer for about 30 minutes, stirring occasionally, by which time the lentils should be very tender.

Taste and add a little more salt and pepper if needed, mix in the lime juice and continue cooking while stirring for 2 - 3 minutes before removing from the heat. Serve as part of an Indian meal or as the main course for a light lunch, with a refreshing salad and chapatis.