Finely chop the onion, garlic and ginger and soften in a little hot oil.
Add the lentils, spices, stock cube and water and stir. The quantities of spices can be varied to increase or decrease the spiciness of the dahl Bring to the boil and simmer gently until the lentils are cooked, this usually takes around 20 minutes. Be careful not to overcook the dahl as the lentils will become mushy.
Remove the cardamon pods. Stir in the tomato purée and serve.