Whisk together two ¼-oz. envelopes instant yeast (about 1 Tbsp. plus 1½ tsp.), 1 Tbsp. agave nectar, and 3 cups warm water in a large bowl. Add 6 cups (750 g) all-purpose flour, 3 Tbsp. extra-virgin olive oil, and 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt; mix with a wooden spoon until combined. Mix vigorously (this is taking the place of kneading, so don’t be gentle) until dough is stretchy, about 2 minutes. Scrape down sides of bowl and form dough into a ball; drizzle with oil and turn to coat. Cover bowl with plastic wrap and let dough rise in a warm, draft-free spot until doubled in size, about 20 minutes.
Grease an 18×13″ rimmed baking sheet with 2 Tbsp. extra-virgin olive oil. Transfer dough to baking sheet; press and stretch nearly to the edges. Cover tightly with plastic wrap and let sit at room temperature until dough is slightly puffed, about 20 minutes.
Meanwhile, place racks in middle and upper third of oven; preheat to 425°. Stir together one 15-oz. can tomato sauce, 2 Tbsp. Calabrian chile paste, and 2 garlic cloves, finely grated, in a small bowl. Taste and season with salt and freshly ground pepper if needed.
Lightly oil your hands. Uncover dough and dimple all over with your fingers, pressing fingertips firmly into dough. Spread tomato sauce mixture over dough; scatter 1 small red onion, thinly sliced, and ½ cup salt-cured black olives, pitted, torn, over.
Bake pizza on middle rack until puffed and golden brown around the edges, 25–30 minutes. Drizzle pizza with oil, then transfer to upper rack. Bake until crust is deeply browned in spots and red onion is lightly charred and crisp in spots, about 5 minutes. Let pizza cool in pan 5 minutes.
Meanwhile, toss 2 large handfuls of arugula (about 4 cups) with 2 tsp. balsamic vinegar in a medium bowl. Drizzle with oil and season with salt and pepper.
To serve, slide a thin metal spatula underneath pizza to
loosen. Cut into pieces and top with arugula.