Sweet Potato, Lentil and Coconut Curry

Serves 6, as a main course

Ingredients:

- 2 large sweet potatoes (mine weighed 1.5kg)
- 2 cups of black olives
- 1 and a 1/2 cups of lentils (500g)
- 2 cans of coconut milk
- 2 cans of tinned tomatoes
- a handful of fresh cilantro leaves
- 1 tablespoon of turmeric
- 1 tablespoon of cumin
- 1 tablespoon of ground ginger
- salt and pepper
- 1 lemon