4 pounds beef cut into large chunks
3 cups water (about)
1 package onion soup mix
1 12-ounce bottle chili sauce
1/2 cup brown sugar
1/4 cup molasses (optional if you want it sweeter)
2 tablespoons worcestershire sauce
1/2 cup onions (optional)

Turn slow cooker to high and let it heat up for about 10 minutes. Add beef and stir to brown on all sides. Reduce heat to low and add onion soup mix and enough water to cover. Add additional onions if desired. Slow cook for 5 to 6 hours or until beef is fork tender. Remove meat from slow cooker and set aside. Pour off most of the liquid from slow cooker and save. Add chili sauce, brown sugar, molasses and worchestershire sauce. Stir until sugar is disolved. Meanwhile shred beef and return to slow cooker. Add enough of the reserved liquid to keep it moist. Stir and allow beef to heat up again. Serve on buns or rolls.