Mince 2 to 4 cloves garlic (4 is great if you love garlic), and set aside. Cut chicken in 1/4-inch slices. Heat olive oil in skillet and saute garlic for 30 seconds, or until fragrance is released. Add chicken and saute until cooked through, 3 to 5 minutes. Season to taste with pepper. Turn off heat and set aside.
Grill or broil bread until lightly toasted, about 1 minute per side.
In bowl, toss together romaine, salad dressing, Parmesan, red onion and chicken. Season to taste with pepper. Pile onto 4 slices of toast, top with remaining toast and serve with tomatoes on the side, if desired. Makes 4 servings.
Picnic packing instructions: Saute chicken in garlic and cool a little. Pack in plastic container and refrigerate.
Place toast in a plastic bag and pack. (Do not seal bag or toast will become soggy.).
Place lettuce in large resealable bowl. Pour salad dressing into plastic container. Spoon cheese into plastic container. Pack red onion and tomatoes, if using, in a plastic bag.
Refrigerate everything except toast until transporting to picnic. Pack everything except toast in cooler with ice or cold packs. (Pack toast at room temperature.).