Place brisket. fat side up. in open roasting pan Sprinkle salt. pepper and garlic over top of brisket; add onions Bake in moderate oven (350'F) 1 hour or until the onions turn light brown Add hot water. cover pan tightly with aluminum foil Reduce oven temperature to 300'F and continue cooking 2 hours Remove brisket and onions to warm platter

To make gravy. combine cornstarch and cold water; stir into cooking liquid. Cook and stir until gravy thickens .