Heat the oven
Set your oven to 425°F (220°C) and line a baking sheet with parchment paper or foil.
Mix the chicken
Toss the shredded chicken with 1/2 cup BBQ sauce in a bowl until everything is well coated.
Prep the flatbreads
Place the flatbreads on the baking sheet, then lightly brush them with olive oil or garlic butter for extra flavor and crisp edges.
Add a little sauce
Spread a thin layer of BBQ sauce over each flatbread if you want even more barbecue flavor.
Layer everything on
Sprinkle half of the mozzarella and cheddar over the flatbreads. Add the BBQ chicken, scatter the red onion over the top, and finish with the remaining cheese.
Bake until melty
Bake for 10–12 minutes, or until the cheese is melted and the edges are golden and crisp.
Finish and serve
Remove from the oven, sprinkle with cilantro, and add any extra toppings you like, such as jalapeños or a drizzle of BBQ sauce. Slice and serve right away while it’s still hot and cheesy.