Combine first 3 ingredients in a large bowl; shape into 6 patties.
Cook patties in hot oil in a large nonstick skillet over medium-high heat 2 minutes on each side or until browned; drain and remove from skillet.
Sauté onion and bell pepper in skillet over medium-high heat 2 minutes or until tender. Stir in tomato sauce, Worcestershire sauce, and dry mustard; bring to a boil. Add patties; cover, reduce heat, and simmer 15 minutes. Uncover and cook 5 more minutes or until patties are no longer pink.