Chicago-Style Stuffed Spinach Pizza

Dough Recipe
1 1/2 pounds (5 cups) bread flour
1 1/2 cups water
1/2 cup extra virgin olive oil
2 teaspoons active dry yeast
1 teaspoon salt

Filling Recipe
2 pounds fresh spinach, washed, dried, and chopped
1/2 pound fresh mushrooms, washed and cut into 1/8" slices (optional)
1 small onion, cut into 1/8" slices (optional)
1 tablespoon extra virgin olive oil
4 cloves garlic, minced
1/2 teaspoon crushed red pepper flakes
16 ounces whole milk mozzarella cheese, shredded
Salt & pepper, to taste

Topping Recipe
28 ounce can whole peeled tomatoes, drained and roughly crushed
5 to 6 fresh basil leaves, chopped
1/4 cup freshly grated Parmesan cheese
(Note: if you prefer, you can substitute your favorite pizza sauce in place of the crushed tomatoes).

In a stand mixer (KitchenAid), mix together the water, oil and yeast until the yeast is fully dissolved. Add the flour and salt. Mix on low until most of the flour has mixed with the wet ingredients. Increase speed and knead until dough forms a cohesive ball and is smooth and silky, about 10 minutes. Transfer dough to a large bowl and cover tightly with plastic wrap. Allow dough to double in bulk, about two hours, punch it down and briefly knead it again to collapse all of the air bubbles. Remove 1/3 of the dough and set aside. Place the remaining dough in bowl and cover.

While the dough is rising, preheat oven to 500° F. 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 onions (in separate batches) in boiling water. Drain in a colander and set aside until needed.

When the dough has doubled in bulk, punch it down and knead it briefly (about 1 minute). Remove 1/3 of the dough and place it back in 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.

Roll out the remaining dough into a 14" circle and place it on top of the filling. Pinch the top and side edges together to seal. Prick the top with a fork to allow steam to escape.

Let the pizza rise an additional 15 minutes in the pan before baking. Bake at 500° F. for 15 minutes, then lower the temperature to 400° F. and bake for 20 to 25 minutes. Add the tomatoes, basil, and Parmesan cheese during the last 10 minutes of baking time.