To make these Greek Veggie Pizza Squares gluten free, use a certified gluten-free puff pastry if available, or substitute with a gluten-free flatbread or gluten-free pizza crust for a similar flavor profile. Be sure to check the labels on the cream cheese, sour cream, dried seasonings, olives, and feta cheese to confirm they are gluten free and free from cross-contact risks. The rest of the recipe can remain the same once those substitutions are made.