01 - Preheat oven to 400°F. Lightly grease a baking dish with olive oil.
02 - Arrange chicken breasts in the prepared dish. Season both sides generously with salt and pepper.
03 - Spread 1 tablespoon of pesto evenly over the top of each chicken breast.
04 - Layer tomato slices over the pesto-coated chicken, distributing evenly among all pieces.
05 - Top each chicken breast with mozzarella slices. Sprinkle grated Parmesan over the top if using.
06 - Drizzle remaining olive oil over the entire dish.
07 - Bake for 25-30 minutes until chicken reaches internal temperature of 165°F and cheese is golden and bubbly.
08 - Remove from oven. Scatter fresh basil leaves over the top and serve immediately while hot.