Makes 8 to 10 servings
1 (5-to-6 pound) well-trimmed brisket
2 large onions, thinly sliced
1 (1-ounce) envelope dried onion soup mix
½ cup dark brown sugar, packed
½ cup tomato ketchup
½ cup chili sauce
Preheat oven to 300 degrees. Spray a large roasting pan with vegetable spray. Rinse the brisket well under cool running water and pat dry with a paper towel. Position brisket in baking pan, fatty side up, and scatter the onions over the top.
In a medium-size mixing bowl, thoroughly combine the soup mix, sugar, ketchup and chili sauce. Drizzle mixture evenly over the brisket and onions. Bake uncovered for 1 hour, basting once or twice. Cover with a lid or aluminum foil and continue cooking until tender, 2 to 2 ½ hours more, basting occasionally.Remove brisket from pan and let sit about 20 minutes before slicing. Use as a main course with the slices repositioned into a roast shape and the onions on top; or use for making warm sandwiches. Serve the pan gravy on the side, defatted if desired.