Preheat the oven to 350°F.
Prepare the gluten free pizza dough on a baking sheet or pizza stone. Parbake the dough according to your homemade recipe or the store-bought package instructions until the crust is just set and slightly firm. Remove from the oven.
Reserve the additional BBQ sauce listed for garnish. Spread the ? cup BBQ sauce (the amount shown in the ingredients) evenly over the parbaked crust, leaving a small border around the edge.
Top the sauced crust with the 1 cup BBQ chicken, then sprinkle 1 cup shredded cheddar cheese over the chicken and scatter the sliced ¼ red onion.
Return the pizza to the preheated oven and bake for 7–10 minutes, or until the cheese has melted to your liking and the crust edges are golden.
Remove the pizza from the oven, add extra BBQ sauce from the reserved amount for garnish, sprinkle cilantro leaves on top, slice, and serve immediately.