Beef brisket requires long slow cooking, making it an excellent choice for the slow cooker, especially when sweetened up with applesauce. For fork-tender sandwiches, be sure to slice brisket across the grain.
Trim fat from meat. If necessary, cut meat to fit into a 3-1/2- or 4-quart slow cooker. Place meat in cooker. In a bowl stir together undrained tomatoes, applesauce, tomato paste, soy sauce, brown sugar, and Worcestershire sauce; pour over meat.
Cover and cook on low-heat setting for 10 to 12 hours or on high-heat setting 5 to 6 hours or until meat is tender. Transfer meat to a carving board, reserving juices. Cover meat and keep warm.
Pour cooking juices into a medium saucepan. Skim off fat. Bring juices to boiling; reduce heat. Boil gently, uncovered, for 10 to 20 minutes or until juices are reduced to desired consistency, stirring frequently. Thinly slice meat across the grain. Place meat on bun bottoms; top with onion slices and drizzle with cooking juices. Add bun tops. If desired, serve with pickles and carrot sticks. Makes 10 to 12 servings.