Preparation / Directions:
Combine ground round, onion, rice, pepper, and egg white in a medium sized bowl; stir well. Divide mixture into 6 equal portions; shape each portion into 1 inch thick patty. Coat a nonstick skillet with cooking spray. Heat over medium high heat until hot. Add patties and cook until browned on both sides (about 4 minutes per side). Transfer to a plate and keep warm. Wipe skillet clean with a paper towel.
Coat skillet with cooking spray; heat over medium high heat. Add mushrooms; saute 5 minutes. Add broth, worcestershire sauce, and salt. Cook for 10 more minutes, stirring occasionally. Return patties to skillet. Cover, reduce heat, and simmer 15 minutes. Transfer patties to serving platter, and keep warm.
Combine cornstarch and water; add to broth mixture, stirring well. Bring to a boil; cook 1 minute, stirring constantly. Spoon sauce evenly over patties.