In a large pot, heat the oil and add the onion, garlic and capsicum and cook until soft. Add the spices and cook for 1 minute. Add beans, tomatoes and salt to taste; cover and simmer for 10 mins until thickened. Spoon in to a greased ovenproof dish.
Lightly crush the corn chips and scatter on top of the beans. Sprinkle over the cheese and bake in the oven for about 15 minutes until the cheese has melted.