Heat the ghee or oil in a large, deep saucepan over a medium-high heat. Stir in the onions, mustard seeds and curry leaves with a pinch of salt and cook for 8-10 mins, stirring frequently, until the onions are caramelised a little around the edges, and the mustard seeds have popped. Mix in the garlic, ginger, chilli, turmeric, coriander, cumin and nigella seeds. Lower the heat to medium and cook for 3-4 mins, until fragrant.

Pour in the vegetable stock, coconut milk and lentils. Rinse out the can of coconut milk with water and add to the pan. Bring to the boil, then stir in the lentils. Cook for 30-40 mins until the lentils are tender and it has reduced. Season to taste and divide into three batches. Will keep chilled for five days in an airtight container, or frozen for up to three months.