Preheat oven to 400°F (200°C). Set out 3 shallow dishes or pie plates. Combine flour, salt, and pepper in one. Pour beaten egg white into the second dish. Transfer Shredded Wheat Biscuit crumbs into third dish.
Dip chicken into flour mixture, turning over to coat both sides evenly; discard remaining flour. Transfer chicken to dish with egg whites, coating both sides, and then to dish with crumbs, coating both sides evenly. Place chicken on parchment paper-lined baking sheet.
Bake 20 min. or until chicken is cooked through. Meanwhile, combine tomatoes and dressing in frypan. Bring to a boil on medium heat; reduce heat to low and simmer 6 to 8 min. or until thickened.
Sprinkle chicken with cheeses. Bake an additional 3 to 5 min. or until cheese is melted. Serve topped with tomato mixture.