-
Pour olive oil into a large frying pan and bring to a medium heat
-
Add the onion, carrot, red pepper, celery and fresh chilli (if using) and sautée until soft
-
Mix in the sweet potato and cook for 2-3 minutes
-
Stir in the garlic, cook for a further minute and then squeeze in the tomato purée
-
Add the herbs, spices and seasoning and mix well
-
Tip the pan into the slow cooker, add the chopped tomatoes and vegetable stock and set the temperature to low
-
After four and a half hours, stir in the beans and cook for a further 45 minutes until fully cooked but not mushy
-
Take care to remove the bay leaf before serving
-
Ladle the steaming chilli into a bowl with cooked rice, sliced avocado, fresh coriander and a squeeze of lime