Step 1

Place racks on upper and lower third of oven; preheat to 450°. Let 1 lb. pizza dough sit in its bag or container until it reaches room temperature, at least 30 minutes—room temp dough is much easier to stretch. Prepare your vegetables while you wait.

Step 2

Start by trimming stem end from 1½ lb. zucchini, then slice crosswise into ¼"-thick coins.

Step 3

Peel 1 onion and thinly slice crosswise into rings to match thickness of zucchini.

Step 4

Toss zucchini, onion, and 2 Tbsp. oil on a rimmed baking sheet; season generously with salt. Spread out in an even layer into corners of pan, taking care not to pile into the middle. Roast on top rack, tossing with a spatula once halfway through, until vegetables are well browned all over and tender, 25–30 minutes. Let cool.

Step 5

Place dough in the center of another large baking sheet and drizzle with 1 Tbsp. oil, then turn to coat. Using your fingers, stretch dough outward from the center all the way to edges of pan. If dough stubbornly springs back, cover with plastic wrap and let rest a few minutes. You may need to do this a few times until your dough cooperates.

Step 6

Drizzle dough with 1 Tbsp. oil and use clean hands to spread oil all across surface. Season dough lightly with salt.

Step 7

Bake dough on bottom rack until beginning to brown and crisp on the bottom, 7–9 minutes.

Step 8

Mix 2 cups ricotta, ¼ cup Parmesan, 2 Tbsp. oil, and ½ tsp. salt in a medium bowl. Using a Microplane, finely grate zest from half of the lemon into bowl with ricotta mixture. Peel 1 garlic clove and use Microplane to grate into bowl. Mix to combine.

Step 9

Dollop ricotta mixture generously over dough. Top with roasted veggies, distributing evenly.

Step 10

Return flatbread to top third of oven and bake until ricotta starts to ooze into vegetables, 6–8 minutes.

Step 11

Immediately grate zest from remaining half of lemon across pizza. Sprinkle ½ cup mint leaves and ½ tsp. red pepper flakes over, then squeeze one half of the zested lemon across surface. Drizzle with oil before slicing.