Squash and potato cream

Serves 4:
1 litre of water, ½ kg of squash, 4 medium-sized potatoes, 1 onion, 300 g of cannellini beans, milk (as needed), salt and pepper.

Clean the squash and cut it into pieces. Boil it with the potatoes. Fry the onion lightly. When the squash and potatoes are cooked, add them to the pan. Use a blender to obtain an even, dense cream. Reach the desired thickness by adding milk. Add salt and pepper to taste. Boil the beans and add them, whole, to the cream just before serving. Add salt and pepper to taste and serve (with croutons if you wish)..