To make gluten-free outdoor pizza, start by preparing a gluten-free pizza dough using a gluten-free flour blend, such as a mixture of rice flour, tapioca flour, and potato starch. Mix the flour with xanthan gum, yeast, salt, and olive oil, and gradually add warm water until a dough forms. Let the dough rise for about an hour.Preheat your outdoor pizza oven or grill to a high temperature. Roll out the pizza dough on a well-floured surface and transfer it to a pizza peel.