6 skinless/boneless chicken breast halves 1 cup bottled light Italian dressing 1/2 cup light Catalina dressing 1/2 teaspoon ground pepper 1/4 teaspoon kosher salt 1 teaspoon chopped garlic 1 10 oz can sliced mushrooms 1 1/4 cups shredded Monterey Jack cheese
Place chicken breasts and all remaining ingredients, except for mushrooms and cheese, in a zip-loc bag. Shake to mix and coat chicken. Marinate at least 1 hour, and up to 6 hours. Preheat grill on medium heat. Grill chicken for 8 minutes on each side. (Discard marinade). The last minute of cooking time, arrange mushrooms on top of each piece of chicken and cover with cheese. Close grill cover and let cheese melt.