To make this recipe gluten free, replace the prebaked thin pizza crust with a certified gluten-free pizza crust. Also confirm that the barbecue sauce, blue cheese, mozzarella, rotisserie chicken, and red pepper flakes are labeled gluten free, since some packaged products may contain additives or be subject to cross-contact. If preparing this pizza in a shared kitchen, use clean utensils, baking sheets, and work surfaces to avoid gluten contamination.