Leek sauce with Balsamic

Sauté two cloves of garlic in 2 ounces oil and 2 ounces of butter. Caramelize the same pan with one or two tablespoons of sugar. Add one lb of chopped leeks or shallots, half glass of white wine and half a glass of Cavedoni Balsamic Vinegar of Modena. Cook for about half an hour, then puree with a vegetable mill. If necessary cook the sauce over low heat until it assumes a creamy consistency. Serve piping hot with boiled vegetables.