Heat the sesame oil in a wide-based pan with a tight-fitting lid.
Add the chopped red onion and cook over a low heat for 10 mins, stirring occasionally, until softened.
Add the crushed garlic clove, ginger and red chilli, cook for 1 min, then add the turmeric and cumin and cook for 1 min more.
Turn up the heat to medium, add the sweet potatoes, stir everything together so the potato is coated in the spice mixture.
Add the red split lentils, vegetable stock, and season with salt and pepper
Bring the liquid to the boil, then reduce the heat, cover and cook for 20 mins until the lentils are tender and the potato is just holding their shape.
Taste and adjust the seasoning, then gently stir in the 80g spinach. Once wilted, add the torn basil leaves and serve with rice and naan bread