In an oven-proof Dutch oven, brown meat in oil on all sides; drain. Top with onions. Combine the ketchup, water and wine; pour over meat and onions.
Cover and bake at 350° for 3 to 3-1/2 hours or until meat is tender. Let stand for 5 minutes. Thinly slice brisket across the grain. Thicken sauce if desired; serve with beef.
Freeze option: Place individual portions of sliced brisket in freezer containers; top with cooking sauce. Cool and freeze. To use, partially thaw in refrigerator overnight. Heat through in a covered saucepan, gently stirring and adding a little water if necessary.