Scarpaccia (zucchini tart)

Name: Scarpaccia (zucchini tart)
Cuisine: European, Italian, Mediterranean
Ingredients: 2-3 small zucchini; 1 very small red onion, or half of a regular-sized one; 1 teaspoon salt; 1 cup all-purpose flour; 1/3 cup fine cornmeal; extra virgin olive oil; 1 teaspoon salt 1-2 sprigs rosemary, finely chopped