Prepare the Dough: In a medium-sized bowl, combine the gluten-free flour, baking powder, and salt. Add the warm water, olive oil, and oregano. Mix until a dough forms. Knead for 3-4 minutes on a floured surface.
Roll the Dough: Preheat the oven to 425°F (220°C). Roll the dough into a circle or desired shape on a baking sheet lined with parchment paper.
Add the Sauce and Toppings: Spread tomato sauce evenly over the dough. Sprinkle with lactose-free mozzarella cheese. Add the zucchini, bell pepper, and shredded chicken on top.
Bake: Bake in the oven for 12-15 minutes or until the crust is golden and the cheese is bubbly.
Serve: Remove from the oven, let cool for a minute, slice, and enjoy! Optionally, top with fresh basil.