Tomatoes release useful juices as they roast. Instead of pouring them away, bring the beans to the tray and let them pick up the olive oil, garlic, and tomato liquid.
Halve 400 g cherry tomatoes and put them in a shallow roasting dish with a sliced garlic clove, two tablespoons olive oil, and a pinch of salt. Roast at 200°C / 390°F until soft and beginning to collapse, roughly 20–30 minutes.
Add a drained tin of white beans, fold gently through the juices, and return to the oven until the beans are hot. Tear basil over the top and serve with bread for two.
If the tomatoes are particularly watery, roast them a little longer before adding the beans. If the dish looks dry, a spoonful of water loosens the sticky juices. The beans should come out coated, not baked into a hard layer around the edges of the dish.