Sauerbraten - cooking recipe

Ingredients

4 lb. sirloin, cut into 1-inch cubes (or leave in 1 piece, if preferred)
2 c. vinegar
1 c. each: water and red wine
2 onions, sliced
1 orange, sliced
1 garlic clove
1 bay leaf
1 Tbsp. salt
1 tsp. each: whole cloves and peppercorns
1/2 tsp. freshly ground pepper
1/4 c. tomato puree
3 Tbsp. flour
2 Tbsp. melted butter

Preparation

In a large bowl, combine the vinegar with the water, red wine, onions, orange, garlic, bay leaf, salt, cloves, peppercorns and ground pepper.
Stir the marinade well.
Add the beef and refrigerate it for 4 to 5 days, stirring it once a day.
Remove the meat and drain it thoroughly.
Brown on all sides in a little heated butter or oil.
Add the marinade, strained of all but the onion slices and 1/4 cup tomato puree.
Simmer the meat for about 2 hours or until it is tender.