STEP 1 - Heat the oven to 200C/180C fan/gas 6. Add the sweet potato to a roasting tin and drizzle over 1½ tbsp of olive oil, 1 tsp paprika, 1 tsp ground cumin and season with salt and pepper. Mix well so the sweet potato chunks are coated in the spices, then roast for 25 mins until cooked.
STEP 2 - Meanwhile, heat the remaining oil in a large saucepan over a medium heat. Add the onion, carrot and celery. Cook for 8-10 mins, stirring occasionally until soft, then crush in the garlic and cook for a further minute. Add the remaining dried spices and tomato purée. Mix well and cook for 1 minute more.
STEP 3 - Next add the red pepper, chopped tomatoes and 200ml water. Bring the chilli to a boil, then simmer for 20 mins. Add the beans and cook for another 10 minutes before adding the sweet potato. Season to taste then serve with rice.