Oven racks should be tiled with unglazed quarry tiles or pizza stones.
Makes 6 - 9 inch calzones
Add yeast to warm water; let it begin to foam. In food processor fitted with plastic blade, mix flour, salt, oil, and yeast mixture. Pulse until dough forms a ball and is smooth and elastic. Put dough aside to rise in a covered bowl for 1 hour. Cut dough into 6 pieces, roll each into a ball, and then cover to keep warm for up to 1/2 hour. Preheat oven to 500°F., lined with quarry tiles.
While the dough is rising, prepare the filling and sauce. For filling, mix the cheeses, egg yolk, oregano, salt, and pepper. Meanwhile, in a large frying pan, heat the oil, then add the peppers and cook for about 3 minutes until they are beginning to soften. Add the garlic, spinach, and dried red pepper flakes. Cook until the spinach is just beginning to dry. Set aside cheese mixture and vegetable mixture.
For sauce, heat oil in a small sauce pan. Add garlic and cook only until fragrant - don't let it brown. Carefully add tomatoes. This will spatter if you add the tomatoes too fast, so guard your clothes and stove. Add oregano and wine, and cook for about 1 minute. Add sugar, salt, and pepper to taste. Continue to cook very slowly to thicken a bit while you finish the calzones.
Roll the balls of dough into 9 inch circles. Keep each of the circles separated from each other with plastic wrap or parchment paper. To form each calzone, cover half a circle with 1/6 of cheese mixture, leaving a 1 inch edge. Cover the cheese with 1/6 of the vegetable mixture. Fold the dough over the filling, this time leaving a 1/2 inch edge, first sealing the top dough to the bottom, then folding the lower edge over the top. Form the remaining 5 calzones in the same way. Cut a few air vents in the top of each calzone, brush with olive oil, and bake for 12 minutes on the quarry tiles.
Serve with the tomato sauce either hot from the oven or after cooling for 30-60 minutes.