Prepare the filling by heating the olive oil in a large skillet and adding the spinach, garlic, chile pepper, salt, and pepper. Cook over high heat, stirring frequently, until the spinach wilts and most of the excess liquid has evaporated. Drain the spinach in a colander and set aside until needed. Blanch the mushrooms and the bowl, covering tightly. Roll the large portion of dough out into a 16" circle. Place the dough into a lightly greased 15" x 2" round deep-dish pizza pan. The dough should come up 2" on the sides. Mix the spinach, mushrooms, and onion together with the mozzarella cheese. Fill the dough shell with the mixture.