Sweet potato, chickpea and spinach curry

1) Heat the olive oil in a large pan and cook the onion, chickpeas, sweet potato, garlic, chilli and spices for five minutes over a medium heat, stirring constantly to prevent sticking.
2) Add the stock and a pinch of salt, then cover the pan, lower the heat and simmer for 15 minutes
3) Add the spinach and cook for a further 5 minutes or until the sweet potato is cooked.
4) Serve with brown rice and naan bread.