Preheat your broiler to high and place an oven rack about 6 inches from the heat source.
Place the pita pocket on a small baking sheet and spread the tomato sauce evenly over the surface, leaving a small border.
Arrange the sliced mushrooms and olives over the sauce.
Sprinkle the grated Cheddar cheese evenly over all the toppings.
Broil for 2-3 minutes, watching carefully, until the cheese is fully melted, bubbly, and slightly golden.
Carefully remove from the oven, let cool for a minute, and then slice into 6 wedges to serve immediately.
Add a sprinkle of dried oregano or Italian seasoning on top of the sauce for a more authentic pizzeria flavor.