Pork Loin With Onions

Preparation:

Preparation: Clean the onions by removing the outer leaves (as you prepare them, keep them immersed in cold water), wash them and drain them. Put a saucepan on the fire with the butter and a few spoonfuls of oil, after a minute pour in the onions, salt and pepper them and bring them almost to cooking keeping the heat very low and the container covered. Stir them occasionally. The onions will form water when cooked, so it will not be necessary to add more. When the onions are almost cooked, collect them in the center of the saucepan and arrange the slices of loin around them, salt them a little and brown them; then add the tomato sauce, cover and continue cooking, always with the container covered.