01 - Preheat your oven to 400°F. Grease a baking dish with a small amount of olive oil.
02 - Place chicken breasts in the prepared baking dish. Season both sides generously with salt and black pepper.
03 - Spread a generous tablespoon of pesto evenly over the top of each chicken breast.
04 - Arrange sliced tomatoes in a single layer over the pesto-covered chicken.
05 - Top each chicken breast with mozzarella slices. Sprinkle grated Parmesan cheese over the top if desired.
06 - Drizzle the remaining olive oil over the entire dish.
07 - Bake for 25 to 30 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F, and the cheese is golden and bubbly.
08 - Remove from oven, garnish with fresh basil leaves, and serve immediately.