Step 1

In the bowl of your stand mixer fitted with the paddle attachment or your food processor fitted with the metal blade, place the flour, xanthan gum, tapioca starch, yeast, and sugar. Whisk to combine with a separate, handheld whisk. Add the salt, and whisk again to combine well.

Step 2

Add the water and olive oil, and mix on medium speed in your stand mixer or pulse in your food processor until the dough begins to come together. Turn the mixer to high speed or your food processor on and process for about 2 minutes.

Step 3

Transfer the dough to an oiled container with a tight-fitting lid or a greased bowl and cover tightly. Refrigerate the dough for at least an hour and up to 3 days.

Step 4

When you’re ready to make the pizza, place a pizza stone or overturned rimmed baking sheet in the oven and preheat it to 425°F.

Step 5

In a medium-size bowl, reserving a generous pinch of the grated Parmesan cheese and of the dried oregano, place the filling ingredients and mix well. Set the filling and the reserved ingredients aside.

Step 6

Remove the dough from the refrigerator, uncover it, and divide it into two equal portions. Work with one at a time, and place the other back in the container and back in the refrigerator.

Step 7

Sprinkle the dough lightly with tapioca starch, and knead it a bit until it’s smoother. Place the dough on a piece of parchment paper.

Step 8

Sprinkling with more tapioca starch as necessary to prevent sticking, roll the dough into a round about 10-inches in diameter. Keep the dough moving frequently, sprinkling lightly as necessary to prevent sticking. Dust the parchment free of any excess flour.

Step 9

Place half of the filling ingredients on one half of the 10-inch round of dough in a half-moon shape, leaving a 1-inch clean border along the edge.

Step 10

Lift the clean half of the dough from the edge and carefully place on top of the filling. Pinch the edges to seal, pressing out any air trapped in the pocket. If you’re fancy, crimp or twist the edges like a pie.

Step 11

Using a pizza cutter or sharp knife, slice three vents in the top of the calzone. Using a pastry brush, coat the top and sides of the shaped calzone liberally with the egg wash. Sprinkle evenly with half of the reserved grated cheese and herbs.

Step 12

Repeat with the other half of the dough, remaining filling ingredients, egg wash, etc. Using a pizza peel or other large, flat surface, transfer the two calzones to the hot oven (on top of the hot pizza peel or overturned baking sheet).

Step 13

Bake for about 25 minutes, or until puffed and lightly golden brown all over. Remove from the oven, allow to set for a few minutes, then serve hot.

Step 14

You can cool the baked calzones completely, wrap very tightly in freezer-safe wrap, and freeze for about a month.

Step 15

Defrost mostly at room temperature, unwrap and sprinkle lightly with water, and warm in a 300°F oven before serving. Do not freeze the unbaked yeast dough, as freezing may kill the yeast.