Heat the oil in a medium sized saucepan and add the onion and garlic. Fry until it begins to soften and then add the potato and cabbage.
Careful not to get the saucepan too hot at this point or things will stick. After five minutes add the chorizo, cannellini beans, diced tomatoes and chilli flakes then bring to the boil.
Once boiling add the stock and bring to the boil once more. Turn the heat down so the soup is simmering and leave for 20 minutes; stirring occasionally.
Add salt and pepper to taste just before serving and enjoy with crusty bread.