- Remove stems from mushrooms; finely chop enough stems to equal 1 cup.
- Cook chicken with chopped stems and garlic in medium skillet over medium-high heat until chicken is no longer pink, stirring to separate chicken.
- Spoon off any fat. Stir in bread crumbs, green onions, 2 tablespoons soy sauce, egg white, ginger and pepper flakes, if desired; mix well.
- Preheat broiler; line broiler pan with foil. Brush mushroom caps lightly on all sides with remaining 1 tablespoon soy sauce; spoon about 2 teaspoons stuffing into each mushroom cap.*
- Place stuffed mushrooms on rack of prepared pan. Sprinkle with cheese.
- Broil 4 - 5 inches from heat 5 to 7 minutes or until hot.