Philly Shredded Beef Sandwiches

To prepare shredded beef: Trim fat from meat. If necessary, cut the roast to fit into a 4- to 5-quart slow cooker. Place onions and garlic in the cooker. Top with the roast. Combine broth, Worcestershire sauce, mustard, thyme, salt, and cayenne pepper in a medium bowl. Pour over everything in the cooker.

Cover and cook on Low for 11 to 12 hours or on High for 5 1/2 to 6 hours.

Remove the meat from the cooker; remove the onions with a slotted spoon, reserving the cooking liquid. Using two forks, shred the meat; discard fat. Skim the fat from liquid. Add the onions to the meat; add enough liquid to the meat to moisten.

To prepare sandwiches: In a large skillet, cook onion and garlic in hot oil over medium heat about 5 minutes or until tender. Add 2 cups shredded beef (reserve remaining beef for another use), broth, pepperoncini peppers oregano, paprika, black pepper and celery seed. Bring to boiling; reduce heat. Simmer, uncovered, about 5 minutes or until heated through and liquid nearly evaporates.

Place cheese slices on half of the bread slices. Spread mayonnaise on remaining bread slices. Spoon meat mixture over cheese slices. Top with remaining bread slices.