Preheat the oven to 450 F (230 C).Crumble the sausage meat into a large pan. Cook over medium heat, stirring frequently until lightly browned.Discard the cooking fat and set the sausage meat aside.Oil a 15-inch (37 cm) pizza pan and cover it with a pizza dough.Sprinkle half of the mozzarella over the dough.Cover with sliced mushrooms, then cooked sausage, then spread the sauce over the top.Cover with the remaining mozzarella.Cook on the lower grill for 20 minutes or until the crust is golden and the topping is grilled.