Preheat the oven to 400°F. Coat a large baking sheet with cooking spray. Press dough to a 12-inch circle. Bake for 9 minutes.
Sprinkle the cheese evenly over the dough. Top with the tomatoes, mushrooms, sausage, and onions. Bake until the crust is golden and cheese is bubbling, about 12 minutes. Top with the arugula, slice, and serve.