Put the minced beef in a large, dry frying pan and cook for 4–5 minutes over a moderate heat until browned.
Add the onion, capsicum and garlic and cook for a further 5 minutes until the onion is softened. Stir in the tomatoes, stock, beans and spices. Bring to the boil, then reduce the heat and simmer for 20 minutes. Season to taste.
Preheat a broiler to a moderate heat. Divide the chilli beef among four individual heatproof bowls or spoon into a large casserole dish. Sprinkle the cheese in a mound in the centre, then broil for about 1 minute until the cheese begins to melt. (Alternatively, ladle the hot chilli into individual bowls and serve immediately, sprinkled with cheese.)
If you like, serve topped with sour cream, diced avocado and chopped coriander with warmed tortillas on the side.