Chard, Onion and Tomato Calzones

I can't get enough of pizza, but tonight I wanted to try a variation: calzones.

one recipe pizza dough
two 14.5-ounce cans of stewed tomatoes, drained
2 tablespoons olive oil
1 tablespoon dried basil
1 tablespoon dried oregano
salt and ground pepper, to taste
1/2 to 1 teaspoon liquid smoke
1 tablespoon balsamic vinegar
1/2 teaspoon red pepper flakes
1 tablespoon minced garlic
2 tablespoons olive oil
1 onion, chopped
1 bunch chard, rinsed, drained with rib removed
cornmeal

While pizza dough rises, prepare tomato sauce and chard. In large skillet, heat 2 tablespoons olive oil with the tomatoes. Add basil, oregano, salt, pepper, liquid smoke, balsamic vinegar, red pepper flakes and garlic. Simmer and reduce until thick; then remove from heat. Meanwhle, julienne or otherwise cut up the chard and set aside. In a large pot, heat the remaining 2 tablespoons olive oil and add the chopped onion. Saute over medium heat for 10 to 15 minutes or so -- until onions are caramelized a bit. Add the chard and stir quickly for a minute to wilt the greens; remove from heat. Preheat oven to 500 degrees and sprinkle cornmeal on two baking sheets. Divide the pizza dough into eight pieces and roll out into thin circles. Add a little of each filling, then moisten edges with water and fold over, crimping to seal. Place on baking sheets; lash a couple smal vents in the top of each calzone. Bake in preheated oven for about 10 to 12 minutes.