01 -
Heat oven to 275°F. Place brisket in large roasting pan.
02 -
Mix ketchup, onion soup mix and water. Pour over brisket, coating both sides.
03 -
Cover tightly with foil, avoiding contact with meat. Cook 7-8 hours until tender but not falling apart.
04 -
Let rest 1-2 hours before slicing against grain into 1/2-inch slices.