For the dough:
2 1/2 cups sifted pastry (00) flour
1 1/2 cups, plus 2 1/2 tablespoons sifted durum flour
1 1/2 cups, plus 2 1/2 tablespoons sifted semolina flour
1/2 cup polenta
1 1/2 cups water
1 1/2 tablespoons kosher salt
1/4 cup olive oil
For the filling:
1 medium Yukon Gold potato
1/2 small red onion
2 small zucchini
1/2 bunch Swiss chard
2 tablespoons grated Parmesan cheese
Salt and pepper, to taste
1. Preheat oven to 350 degrees. Combine all dough ingredients in a stand mixer outfitted with a paddle attachment. Mix on low speed, until dough pulls away from sides of mixing bowl. Put dough in a bowl, and cover. Set aside.
2. Roughly chop all of the vegetables. Put into food processor and pulse for about 30 seconds into small bits (but not pureed). Remove to a bowl and mix with the cheese. Season with salt and pepper to taste.
3. Using a pasta roller, roll out sheets of dough until 1/8-inch thick. Press sheets together until you have enough dough to cover the bottom of a 1/4 sheet tray or a casserole (13-by-9-inch), with some extra hanging over the sides. Repeat, so you have a second dough sheet, the same size as the first, to top the torta. Place one sheet in the tray.
4. Add the vegetable mixture, spreading it out so it is a half-inch deep. Top with second layer of dough, stretching it to fit across the vegetables. Pinch the excess top and bottom dough together, sealing the vegetables inside. Cut off excess dough, making a clean edge. Poke a few fork holes throughout the torta to vent. Bake for 50 minutes, or until just darker than golden brown. Let rest for one hour. Cut into squares, and serve.
Per serving (based on 12 hors d'oeuvres or 4-6 appetizer portions): 318 calories, 9 grams protein, 57 grams carbohydrates, 1 gram sugar, 6 grams fat, 1 milligram cholesterol, 891 milligrams sodium, 4 grams dietary fiber.