Sauté the shallots in the oil in a large saucepan set over a low-medium heat. After 5 minutes they should be soft but not coloured. Add the ginger and fresh or ground turmeric. Cook, stirring, for 1-2 minutes then add the remaining spices and cook for 1 minute. Add the lentils, cherry tomatoes, coconut milk and 2 cans of water (800ml); season.
Bring to the boil, stir well and partially cover. Simmer for 10 minutes then stir in the sweet potato, partially cover and simmer for 35-40 minutes, stirring now and then. Uncover and season if needed. Stir in the kale and simmer, stirring often, for 5 minutes, until the greens have softened. Finish with the lemon juice and a handful of coriander, if liked. Serve with steamed rice or naan bread. (Warn your guests about the whole cardamom pods.)
