Zucchini in riquagghio with an egg

Add chopped onions, diced zucchini and chopped potatoes to a saucepan. Add olive oil and salt, cover the pan and simmer on a low flame; if necessary, add some water. When the potatoes are cooked, add the chopped cherry tomatoes and continue cooking. When the zucchini and potatoes are both cooked add chopped basil leaves and break the eggs over them. Cover with lid and cook for an additional two minutes.