In a large bowl, crumble sandwich bread. Add milk and egg. Toss together with a fork. Set aside to soften.
Meanwhile, in a large nonstick skillet, cook bacon until crisp. Crumble and set aside. Spoon off all but 2 Tbsp. of the bacon fat, reserving for later. Add onion to skillet and cook over medium high heat until tender, about 5 minutes. Add to bread mixture and beat with fork until smooth. Add beef, Worcestershire sauce, salt, pepper and 1/4 cup Smoky Red Mustard. Mix with clean hands and shape into 4 oval patties.
Heat skillet over medium high heat, cook patties 7 minutes on each side or until cooked through. Cover pan with lid ajar to allow steam to escape. Spoon additional Smoky Red Mustard over each patty. Cover to heat through. Remove patties to serving platter and garnish with bacon.