1 c. ketchup
1/2 c. water
1 tsp. instant minced onions
1 tsp. salt
1/8 tsp. pepper
1 tbsp. cider vinegar
1 1/2 tsp. white horseradish
1 1/2 tsp. prepared mustard

Mix all together and pour over brisket (fat side up). Bake covered 3 to 3 1/2 hours at 300 degrees.

Separate meat and gravy to refrigerate. Slice, add gravy and cover all with foil to reheat.