Fry the onion in 1 tablespoon of butter until golden. Add half of the sliced garlic, cumin, mustard seeds and cloves. Cook gently for about 5 minutes. Stir in the turmeric and chili powder until well blended.
Add the lentils, water, coconut milk, ginger, tomatoes and spinach. Bring to a simmer, add pepper and cook gently, stirring occasionally, for 30-40 minutes or until the lentils are soft and have dissolved into the liquid.
Remove the pan from the heat.
Melt the remaining butter in a small pan. When it gets frothy, add the rest of the garlic and stir until it starts to colour. Add this to the lentil mix.
Add the lime juice, coriander, mint and salt. Cover with lid and leave to sit for 10 minutes. Remove ginger chunks and serve with nann bread or any other type of flat bread.