Pour in the beans, corn, crushed tomatoes, and vegetable stock. Bring to a simmer, then reduce heat and simmer for 20 minutes.
1 can (14 oz / 400 g) black beans
1 can (14 oz / 400 g) red kidney beans
1 can (7 oz / 200 g) sweetcorn
1 can (14 oz / 400 g) peeled tomatoes
4 cups vegetable stock