Preheat the oven to 425 degrees. Brush a large baking pan or pizza pan with olive oil. Set aside.

On a lightly floured surface, roll the pizza dough out into a 14-inch wide circle. As you roll the dough, be sure to keep the surface where you are rolling the dough well floured.

Careful roll the dough around the rolling pin and transfer the dough to the prepared baking sheet or pizza pan.  Set aside.

Make the filling.  In a medium bowl, mix together the mayonnaise, ricotta cheese, goat cheese, asiago cheese, chives, thyme leaves, and pepper until well combined.

Spread the mixture on the pizza dough, leaving a 2-inch border around the edges.

Pour the olive oil into a skillet and warm over medium-high heat.

Add the garlic and thawed spinach.  Stir to coat everything with the oil.

Saute until the garlic is fragrant, but not browned – about 3 minutes.

Add the artichoke hearts and stir to combine.  Remove from the heat and set aside to cool.

When the mixture has cooled to room temperature, stir in the diced mozzarella.

Spoon the mixture into the center of the pizza crust.  Gently press the spinach mixture down into the sauce, spreading it out evenly over the sauce, taking care to leave the 2-inch border without sauce or vegetables.

Very lightly brush the border of dough with water.

Pull and fold the border of dough up around the spinach-artichoke mixture, pinching the folds together.  Leave the center open.

Brush the outside of the dough with the beaten egg.

Bake in the preheated oven until golden brown, 40-45 minutes.  Check the bottom of the crust by gently lifting up a side with a spatula and ensuring that it isn’t getting too brown.  Lower the temperature if the bottom of the crust gets too dark.

Carefully transfer the crostata to a wire rack to cool for 15 minutes.

Cut into wedges and serve warm or room temperature.