Thoroughly wash the lentils in cold running water and set aside.
In a medium size saucepan heat the butter or ghee over medium heat. Add the chilli, turmeric, cumin seeds, onion, garlic and ginger and cook for 5 - 6 minutes or until the onions start to colour.
Stirring constantly add lentils, stock and salt. Bring to a boil, cover with a lid, lower to a gentle simmer for about 30 minutes. Stir occasionally to ensure the lentil do not stick to the bottom of the pan.
Serve hot with a warm naan and garnish with a dollop of Greek yoghurt, fresh coriander and thinly sliced red chilli if desired.