Get the oil in a saucepan and bring it up to a medium-high heat.
1 tablespoon rapeseed oil
Add the onion and fry until soft and translucent.
1 onion
Chuck the garlic, ginger, chilli and spices in and stir.
4 cloves garlic, 1 inch fresh ginger, 1 green chilli, 2 teaspoon cumin seeds, 1 teaspoon yellow mustard seeds, 2 teaspoon ground turmeric, 1 teaspoon garam masala
After a couple of minutes when the spices have become fragrant, add the carrots and tomatoes and cook for another two minutes.
2 carrots, 2 tomatoes
Pile in the lentils, then the coconut milk and water, and give it a good stir.
1 cup red lentils, 400 ml coconut milk, 200 ml water
Bring to a boil and immediately reduce to a simmer.
Simmer for 15 minutes, stirring frequently.
Give the lentils a quick check and make sure they're cooked, if they're not quite there, give them another 5 minutes.
Stir in the coriander and season with salt to taste. If you're happy with consistency, serve with naan bread or roti.
2 tablespoon fresh coriander