The original recipe is here, and I only modified it slightly. Here it is, copy/pasted with the modifications.
1 c quinoa
1 1/2 cups very hot water
1/4 c grapeseed oil or olive oil
1/2 t kosher salt
1/2 t garlic powder
1/2 t Italian seasoning
Mix the quinoa and hot water in a bowl and soak overnight.
Preheat the oven to 450 degrees. Use a large, 12-inch cast iron skillet, and brush with oil. Place in oven to preheat.
Place the quinoa in a blender. Add the seasonings and blend. Add more water if needed, until the batter resembles a thick pancake-style batter.
Once the oven is heated to temperature, pour the batter into the skillet and quickly spread it out evenly across the bottom. Place in the oven and bake for about 10 minutes, or until the underside is well-browned and starting to crisp. Use a large spatula and carefully flip the crust. Bake for an additional 10 minutes.
Remove from oven, and top with desired toppings. As with any pizza, be careful not to overload on toppings or the crust will get a bit soggy. Return to oven for 5-7 minutes, or until the crust is well-browned on the bottom and crisp. Remove from the skillet and transfer to a cutting board or plate. Slice and serve!