Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
Place the naan or flatbread rounds on the prepared baking sheet and brush lightly with olive oil.
Spread basil pesto evenly over each flatbread, covering the surface almost to the edges.
Top with shredded chicken, mozzarella cheese, cherry tomatoes, and sliced red onion.
Season lightly with salt and black pepper.
Bake for 10–12 minutes, or until the cheese is melted and bubbly and the edges are golden brown.
Remove from the oven and allow the Pesto Chicken Flatbread to cool for 1–2 minutes.
Garnish with fresh basil leaves, red pepper flakes, or a drizzle of balsamic glaze if desired.
Slice and serve warm.