Butter beans are generous enough to make a pan of tomatoes feel like a meal. Their soft interiors also mean they benefit from a little restraint: energetic stirring turns them into a different, rather pastier dish.
For two people, soften a sliced onion in a tablespoon of olive oil. Add a sliced garlic clove and a pinch of dried oregano. Pour in a 400 g tin of tomatoes and simmer until the raw edge of the tomato has mellowed, about 15 minutes.
Fold in a drained 400 g tin of butter beans. Simmer gently until hot, adding water if needed. Taste for salt and finish with torn basil or parsley. Serve with bread, rice, or a cooked grain.
If the beans break a little, that is useful: they thicken the sauce. If they are collapsing completely, stop stirring and use a broad spoon to lift portions out. This is a good place for a shallow bowl rather than a flat plate.