01 -  Preheat grill or grill pan to medium-high heat. 
 02 -  Brush chicken breasts with olive oil and season with salt, pepper, and garlic powder. 
 03 -  Grill chicken for 5–6 minutes per side, or until fully cooked (internal temperature 165°F/74°C). Let rest 5 minutes, then slice thinly. 
 04 -  Preheat oven to 425°F (220°C). 
 05 -  Place flatbreads on a baking sheet. Spread each evenly with basil pesto. 
 06 -  Top with sliced grilled chicken, mozzarella cheese, and cherry tomatoes (if using). 
 07 -  Sprinkle with Parmesan cheese. 
 08 -  Bake for 8–10 minutes, or until cheese is melted and bubbly and edges are crisp. 
 09 -  Remove from oven, garnish with fresh basil leaves, slice, and serve warm.