Wash the zucchini and peel the onion. Slice both into thin rounds and set them aside.

Combine zucchini and onion in a bowl, sprinkle with salt, and let sit for about 15 minutes.

Drain the salted vegetables using a colander, pressing to extract excess moisture.

In a mixing bowl, whisk together flour and polenta. Stir in the extracted liquid until smooth.

Fold in the drained vegetables and season with pepper and additional salt if needed.

Preheat your oven to 200°C (400°F) and prepare a baking sheet with parchment paper and olive oil.

Drop dollops of the batter on the baking sheet, drizzle with more olive oil, and add extra polenta if desired.

Bake for 35-45 minutes until golden brown and crispy.

Let cool slightly, top with basil, cut into squares, and serve warm or at room temperature.