Prepare the toppings by cooking sausage in a skillet over medium heat, crumbling as it browns on all sides. Drain and set aside.
Cook sliced bell peppers and onions in another skillet with olive oil over medium heat. Stir often until onions start to caramelize. Remove from heat and set aside.
Cook sliced mushrooms in another skillet with olive oil, salt and pepper over medium heat. Stir often, cooking until mushrooms are softened and start to brown. Remove from heat and set aside.
Stir the pizza sauce together in a bowl.
Prepare a grill fire using a pizza stone to 450°.
Make the pizza dough and divide into 3 equal pieces.
Roll each pizza dough into a 8 inch circle.
Sprinkle a pizza peel well with cornmeal.
Place the dough over the cornmeal. Press the edges of the dough to form an edge.
Add pizza sauce, spreading evenly to the edges.
Sprinkle with mozzarella cheese.
Add sausage, onions, peppers and mushrooms.
Top with more mozzarella cheese.
Sprinkle pizza stone with cornmeal.
Slide the pizza onto the pizza stone and close the lid. Lower grill temperature to around 350°.
Continue to rotate pizza about every 3- 5 minutes, cooking until pizza is well browned on the bottom and the cheese starts to bubble. Total cooking time should be about 15- 20 minutes.
Remove from grill and cool about 5 minutes before slicing.
Repeat with remaining ingredients to create 3 pizzas.