01 - Preheat oven to 400°F. Lightly grease a baking dish with olive oil.
02 - Place chicken breasts in 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 - Arrange tomato slices over the pesto-coated chicken, distributing evenly.
05 - Place mozzarella slices over tomatoes. Sprinkle with grated Parmesan if using.
06 - Drizzle remaining olive oil over the dish. Bake for 25-30 minutes until chicken reaches internal temperature of 165°F and cheese is golden and bubbly.
07 - Remove from oven. Garnish with fresh basil leaves and serve immediately.