Preheat the oven to 450 degrees F.
Sprinkle the cornmeal on a large baking sheet or pizza pie pan. Lay the prepared pizza crust on top of the corn meal.
With a medium to large size spoon, add about half of the pizza sauce over the top of the crust (add more if you like a lot of sauce).
Evenly spread the sauce over the crust with the back of the spoon (leave about 1 inch of empty space around the edges).
The remaining sauce can be used for making small size pizzas on English muffins or slices of French bread. Or it can be frozen for future use.
On top of the sauce, add small pieces of ricotta cheese around the entire pizza. Then add the mozzarella cheese evenly over the top of the pizza.
Next, lay the slices of pepperoni around the entire pizza.
Top with pieces of ham, cooked sausage, sliced mushrooms, and black olives over the entire pizza.
Sprinkle grated Parmesan cheese on top of the entire pizza.
Bake the pizza in the middle of a preheated oven until the cheese melts and the edges of the crust are slightly golden (about 15 minutes).
Cut the pizza with a pizza cutter and serve warm.