Combine 1/3 bottle of balsamic vinaigrette dressing with the chicken tenders in a bowl. Toss together sliced mushrooms with 1/3 bottle of dressing in a separate bowl. Reserve the remaining 1/3 bottle. Allow the chicken tenders and mushrooms to marinate for at least 30 minutes.

Preheat the oven's broiler, and set the oven rack about 6 inches from the heat source.

Remove the chicken tenders and mushrooms from the marinade, and drain off the excess. Broil the chicken and mushrooms until the chicken is browned and cooked through, 5 to 8 minutes. Remove the chicken and mushrooms from the heat, and slice the chicken tenders into bite-sized pieces.

To serve, divide the chopped romaine lettuce between four plates, and top each with broiled chicken and mushrooms. Sprinkle each plate with cherry tomatoes, mozzarella cheese, and sliced basil leaves; serve with the remaining vinaigrette dressing.