Boiled Beef with Tomato Sauce

Description
In Romanian: Rasol cu sos de rosii

Ingredients

 * 2 lbs/1 kg boiled beef,
 * 2-3 onions,
 * 1 tablespoon tomato paste or 1 lb/500 g boiled and strained tomatoes,
 * 1 cup beef broth or milk,
 * 1 tablespoon butter,
 * 1 tablespoon vinegar,
 * a little sugar,
 * salt,
 * flour

Directions

 * 1) Cut the cold meat in bite sizes, place on a platter and cover with the following sauce: fry the chopped onion in butter until softened.
 * 2) Add the flour, mix well and pour the broth or milk on top. Add the tomato paste or chunks of peeled and seeded tomatoes, salt and pepper.
 * 3) Cover the pot and let it boil at slow heat until the liquid is entirely gone. Serve with polenta.