this is how i make a calzone, you can put whatever you want in it. you will need meat, onion, mushrooms,garlic, green pepper, a canned pillsbury pizza dough, a can of pizza or spaghetti sauce and lots of cheese.
fry, in some olive oil, chopped onion, garlic, mushrooms, green peppers, your meat and whatever else you would like. (jalepenos are good.) season to taste with oregano or basil or whatever.
spread some flour or cornmeal on a cookie sheet to keep the dough from sticking. put the dough on the cookie sheet and spread it out as much as possible without tearing it. spread your sauce liberally over the crust.
put your cooked meat and veggies in the center, top with a pile of cheese. fold the sides and ends over the top so that the calzone is enclosed. sprinkle some sheese on top and poke some vent holes with a knife.
cook at 425 for 15 to 20 mins until crust is how you like it. dig in.