Recipe

1. Preheat oven to 500°F with rack in lowest position. Sprinkle cornmeal on a large baking sheet.

2. Cook onion with 1/4 teaspoon salt in 2 tablespoons oil in a large heavy skillet over medium heat, stirring occasionally, until beginning to brown, 8 to 10 minutes. Add garlic and cook until fragrant, about 1 minute. Add spinach and cook, stirring frequently, until wilted, about 2 minutes. Stir in red peppers, olives, and pepper to taste. Remove from heat.

3. Roll out dough on a lightly floured surface with a lightly floured rolling pin into a 14-inch round, then cut into quarters. Roll out 1 quarter into an 8-inch square (keep remaining pieces covered) and arrange with a corner nearest you. Put one fourth of filling on lower half, leaving a 1-inch border, and top with 4 pieces of cheese. Fold dough over to enclose filling. Seal edges. Beginning in 1 corner, stretch sealed edge outward, pinching and rolling dough up over edge to resemble a rope, working your way around. Transfer to baking sheet. Make 3 more calzones in same manner. Cut 3 steam vents in top of each and brush with remaining tablespoon oil.

4. Bake until golden-brown, 13 to 15 minutes. Cool 5 minutes before serving.

5. Cooks' note: Filling (without cheese) can be made 1 day ahead and chilled. Bring to room temperature before using.