Preheat your oven. If you are using a conventional home oven, bring it to the highest temperature (250°C - see notes for baking tray).
Slice the mushrooms and garlic cloves.
In a pan, over medium-high heat, add the oil and mushrooms, and sauté for a few minutes, stirring occasionally.
Once they start getting a golden colour, add the garlic, some salt and pepper, and sauté for a couple of minutes.
Then deglaze with the wine, add the fresh oregano, and cook for 2 more minutes until the wine has evaporated.
Remove from the heat and let them cool down.
Carefully place the dough on a clean surface that you have sprinkled with some flour, and add some extra flour on top of the dough.
Gently press the dough from the centre outward with your fingers, rotating it as you go, until it forms a large rectangle or circle.
Unlike pizza, calzone requires a generally flat surface, so keep that in mind when rolling out the dough. You can even use a rolling pin.
Sprinkle a little flour or semolina on your pizza peel or a wooden chopping board, and lay the dough on it.
Before you start adding ingredients, shake the pizza peel/board back and forth to make sure that the dough moves. Then place the ingredients in half of the dough, starting with the mushrooms, half of the passata, and then the cheese.
Fold over and tightly crimp the edges. Cut air vents, add the remaining tomato passata on top, and a sprinkle of oregano.
Carefully slide the prepared calzone from the peel or board onto the preheated oven baking tray or preheated pizza stone.
In a home oven, bake it for 5-6 minutes or until golden. If you are using a pizza oven, it can take from 2-4 minutes.
If using the Piana gas pizza oven, use the wheel to rotate it.
Once baked, remove from the oven, cut, and enjoy!