How to Make It
Heat the oven to 450°. In a large nonstick frying pan, heat 1 tablespoon of the oil over moderately high heat. Add the Swiss chard and 1/4 teaspoon each of the salt and pepper and cook, stirring, until the chard is wilted and no liquid remains in the pan, about 3 minutes. Set aside to cool. Squeeze out any remaining liquid, if necessary.
In a large bowl, combine the ricotta, mozzarella, Parmesan, sun-dried tomatoes, basil, and the remaining 1/4 teaspoon each of salt and pepper. Add the chard and mix well.
Oil a large baking sheet. Cut the pizza dough into four pieces. On a floured surface, roll or stretch each of the pieces into an 8-inch round. Spoon a quarter of the cheese mixture onto one half of each round, leaving a 3/4-inch border. Brush the border with water and then fold the dough up over the filling. Seal the edges by folding the edge of the dough over and pinching it. Transfer the calzone to the prepared baking sheet. Brush with the remaining tablespoon of oil and bake until golden, 15 to 20 minutes.