1Set oven control to broil. Place bread slices on ungreased cookie sheet. Spray bread with cooking spray; sprinkle with cheese. Broil with tops 4 to 6 inches from heat 1 to 2 minutes or until light brown; set aside.
2In 10-inch skillet, cook beef, bell pepper and garlic over medium-high heat 5 to 7 minutes, stirring occasionally, until beef is brown; drain. Stir in tomatoes, pizza sauce and mushrooms. Cook 1 to 2 minutes or until hot.
3Place 2 toasted bread slices on each of 4 serving plates; top with beef mixture.