Peel and finely slice the onions.
Heat 4 spoons of oil in a saucepan, add the onion, the peeled and thinly sliced carrots along with the turnip tops. Add 25 ml of water and cook for another 5 minutes. Thoroughly drain and slice the peeled tomatoes into fillets.
Rinse the cannellini beans and add to the vegetables. Cook for another 5 minutes. Season with salt and black pepper, remove from heat.
Toast the bread, rub some garlic over the surface, top with vegetables and serve with a drizzle of oil.