How to Make It
Place oven rack on lowest shelf. If you have a stone, place it on rack. Preheat oven to 550°F, or your oven's highest temperature, for 45 minutes.
With motor running, drop garlic into feed tube of a food processor. Scrape down sides of bowl. Add chickpeas, tahini, lemon juice, salt, pepper and 2 Tbsp. water. Puree until smooth.
Dust a 14-inch-wide pizza peel with cornmeal, then flatten dough on top. Using lightly floured fingers or a floured rolling pin, stretch dough into a 13- to 14-inch round. (Sprinkle peel with more cornmeal if necessary to make sure crust slides around easily on peel.) Brush 1 1/2 Tbsp. oil over crust.
Spread hummus over crust, leaving a 1-inch border. Scatter peppers, feta, olives and crushed red pepper over pizza. Drizzle remaining 1 1/2 Tbsp. oil over pizza.
Carefully slide pizza onto stone. Bake until crust is golden brown on edges and on bottom (lift an edge to check) and cheese is lightly browned, about 8 minutes. Transfer to a cutting board. Sprinkle onion slices over pizza. Let rest for a minute; slice and serve.