Heat the oil in a sturdy pot
Add the cumin seeds, then onion, then garlic and ginger. Cook gently until everything is soft and smells great
Add the curry powder then mix in the tin of tomatoes to form your base
Add the potatoes, then stock and lentils. Bring to the boil then reduce the heat and allow to simmer for 30 minutes, stirring occasionally
When the potatoes soften, mash the mixture till all the big chunks of potato fall apart
Finish by adding in the coconut milk, coriander and lime juice
