A calzone is merely a folded, stuffed pizza. Virtually any mixture will do. To create a calzone, roll your favorite pizza dough to a 1/4-inch thickness, add the filling (e.g. drained ricotta, finely chopped fresh basil, a sprinkling of freshly grated parmesan, and freshly grated pepper) and a few slices of fresh mozzarella, fold over and press the edges together (you can crimp or fold the edges to ensure nothing leaks out). With a knife or fork, poke a few holes in the top of the calzone to allow steam to escape, and bake at 500 degrees for 15 to 30 minutes, until the top is golden brown.
Really, good additions — sausage, about ¼ inch slices, really, very finly chopped, drained cooked spinach — etc.
You can find this and other recipe(s) by tapping here on the Home Cookin' index.