Heat 1 tbsp of olive oil in a large saucepan over a medium heat. Add the onion and curry paste, mix well, then cook for 10 minutes, stirring occasionally, until the onion is soft and golden.
Add the chilli, coriander and chickpeas, and continue to cook for 5 minutes. Add the tomatoes and sweet potato, and bring the mixture to the boil. Reduce the heat to a simmer, then cover and cook for 15 minutes.
Remove the lid, then cook for a further 10 minutes, stirring occasionally, until the sweet potato is cooked through and the sauce thickened.
Stir in the coconut milk, bring the mixture to the boil, then turn off the heat. Stir in the spinach, and allow the curry to rest until the spinach is wilted. Serve as is, or alongside some rice, and enjoy