Sweet and sour onions (cipolle in agrodolce)

Serves 4.

gr. 400 onions, vinegar, sugar, olive oil, salt.

Peel the onions and cook in salted water, removing them when they are still a lot to slightly underdone. Drain, put them in a pot with half a cup of oil. Fry a little, then sprinkle with half cup of vinegar and a teaspoon of sugar. Cover and cook for about ten minutes.