Cut four sheets of foil, about 12-inches long. Add chicken to the center of each foil; season with salt and pepper, to taste.
Fold up all 4 sides of each foil packet. Top chicken with pesto, tomatoes and mozzarella.
Fold the sides of the foil over the chicken, covering completely and sealing the packets closed.
Place foil packets in a single layer on a baking sheet. Place into oven and bake until the chicken is completely cooked through, reaching an internal temperature of 165 degrees F, about 25-30 minutes.*
Served immediately, garnished with basil, if desired.
Notes
*Cooking time will vary depending on the size and thickness of the chicken.