Cut the chorizo into slices and fry in a saucepan without adding any oil. Then take it out. Cut the onions and garlic into cubes. Cut the chillies into fine slices.
First sweat the onions, then add the cumin powder, the chillies and the garlic. Let everything go a little and add the chorizo, beans and tomatoes.
Bring to the boil once and serve with fresh bread.