Preparation

• Using a mandolin or sharp knife, slice the zucchini and onion as thinly as possible. Place the vegetables in a medium bowl, then add 1 teaspoon of the salt and use your hands to massage it into the vegetables.
• Transfer the mixture to a fine mesh sieve set over a bowl. Place a small plate on top and add a heavy weight on top, like a large can of tomatoes. Drain for at least 1 hour, or up to 3 hours. (Reserve the drained liquid for step 5.)
• When you’re ready to bake, preheat the oven to 450°F with a rack in the center. Line a baking sheet with parchment, drizzle 1 tablespoon (12g) of the olive oil over the parchment, then use a pastry brush or your fingers to spread it evenly. (Be sure to coat the sides of the pan too.)
• In a large bowl, combine the flour, cornmeal, Parmesan, cornstarch, spices, and the remaining ¼ teaspoon salt.
• In a liquid measuring cup, measure the drained liquid from the vegetables, then add enough water to equal 1 ¼ cups plus 1 tablespoon (300g). Add the remaining 1 tablespoon (12g) olive oil and stir to combine.
• Pour the wet ingredients into the dry ingredients and stir until smooth. Add the vegetables and stir until they’re evenly distributed.
• Transfer the mixture to the prepared pan, then use wet hands to distribute it as evenly as possible, all the way to the edges of the pan. The mixture will be very thin.