03Meanwhile, heat half the remaining oil in a skillet. Add the red pepper and onion and saute until barely beginning to brown. Stir in the garlic, saute a few seconds longer, then remove from the heat.04When the dough has doubled, punch it down and divide it into four equal portions. Roll each into a circle about 12 inches in diameter.05Preheat oven to 450 degrees. Oil a large baking sheet.06Lightly brush the dough circles, to within an inch of the edges, with the remaining oil. Scatter the sauteed vegetables over half of each dough circle. Arrange the tomato slices on the vegetables, then spinkle with the prosciutto. Crumble the goat cheese on top, then add the mozzarella.07Fold each dough circle in half, brush the edges with warm water and pinch them tightly closed. Cut one or two slashes in the top to make steam vents.08Place on the baking sheet, place in the oven and bake until puffed and lightly browned, about 25 minutes.09Allow the calzones to cool briefly, then serve.