- Place the coconut oil and onion in a 20 cm (8 inch) cast-iron saucepan* and cook over medium heat, stirring occasionally, for 5 minutes or until the onion is nearly translucent, soft and lovely.
- Stir in the garlic, ginger, turmeric, ground coriander, cumin seeds and curry powder and cook for another 2–3 minutes until aromatic.
- Add the coconut milk, sweet potato and, if necessary, a little water to come just underneath the vegetables (the water should not cover the vegetables).
- Place the lid on top of the pan and cook over low heat for 30 minutes or until the sweet potato is tender when pierced with a knife.
- Gently stir in the cooked black lentils and stir until warmed through.
- Add the lime juice and coconut sugar to taste, then scatter with chopped coriander just before serving.
It’s important to use a saucepan no bigger than 20 cm (8 in) in diameter. This will ensure there’s enough liquid to come just below the vegetables without having to add water.