Preheat your oven to 200 degrees.
Spritz a baking tray with low calorie cooking spray. Place the wrap on top, and spread the tinned tomatoes over one half, being careful not to get too close to the edge.
Add the mozzarella, ham, mushrooms, and onions. Brush the outer edges of the wrap with the beaten egg.
Fold over the wrap to form the calzone, and use the back of a fork to crimp together.
Brush the calzone with the beaten egg, and place in the oven for 10-15 minutes or until golden brown.
Remove from the oven, turn over, brush the opposite side with the beaten egg, and place back in the over for 10-15 minutes or until golden brown.
Serve and enjoy!