In zip-lock plastic bag, make marinade by mixing together olive oil, lemon juice, Worcestershire sauce, mustard, garlic salt and pepper. Add chicken. Refrigerate 15 minutes. On shallow plate, mix crushed croutons and Parmesan cheese. Remove chicken from marinade and drain; reserve marinade. Add chicken, one piece at a time, to crouton mixture, dredging to coat. Place chicken on greased shallow baking pan; drizzle reserved marinade over chicken. Bake in 400 degrees F oven about 18 minutes or until fork can be inserted in chicken with ease. Arrange lettuce leaves on serving plate; place chicken on lettuce and garnish with lemon slices. Make 4 servings.