• Preheat the oven to 450°F.

Crust

• Drain the pre-soaked quinoa in a fine-mesh sieve and rinse. Transfer to a high-powered blender and add 1⁄4 cup water, the seasoning, salt, and garlic. Puree, adding more water if needed, to make a very smooth batter.
• Place a 12-inch cast-iron skillet or a rimmed pizza pan in the oven for 5 minutes. Add the avocado oil, return the pan to the oven, and heat for 5 minutes. Carefully remove the hot pan, and tilt it so the oil covers the bottom evenly. Carefully pour the batter into the center of the pan—don’t pour too quickly or the oil could splatter. Spread the batter evenly. It should be 1⁄4 to 1⁄2 inch thick, depending on the pan. (If using a pizza pan, it may not reach all the way to the edges.)
• Bake for 15 minutes, or until the top becomes somewhat dry and the edges golden. Carefully slide a large spatula under the crust to loosen it, then slowly flip it over, being careful not to splash any hot oil. Return to the oven and bake for 10 minutes.

Toppings

• Carefully transfer the crust to a rack. Blot off the oil. Remove excess oil from the skillet or pan, leaving just enough to coat the bottom. Place the crust back in the pan and spread the pesto over the crust, then top evenly with the fennel and onion. Bake for 10 to 15 minutes to warm the toppings through.
• Toss the arugula with the olive oil, salt, and pepper. Add to the top of the pizza, cut into wedges, and serve immediately.