Heat grill to medium-high. Season chicken breast with salt and pepper on both sides and place on hot grill. Cook for about 5 minutes on each side, or until a thermometer inserted in the center of the thickest part of the chicken breast registers 165°F.
Top with Provolone, close lid on grill and let sit until cheese is melted, approximately 1 minute.
Remove chicken from grill and slice in two equal pieces.
Spread pesto on 1 slice of toasted bread. Layer with chicken and roasted red pepper. Top with second toasted bread slice and enjoy.