Pide (Turkish Flatbread) with Cheese and Spinach

In a large bowl, combine flour, yeast, sugar, and salt. Add warm water and olive oil. Mix until a shaggy dough forms.

Turn the dough out onto a lightly floured surface and knead for 5-7 minutes, or until smooth and elastic. Place the dough in a lightly oiled bowl, turning to coat. Cover and let rise in a warm place for 1 hour, or until doubled in size.

While the dough is rising, prepare the filling. Heat a tablespoon of olive oil in a large skillet over medium heat. Add the chopped onion and cook until softened, about 5 minutes. Add the minced garlic and red pepper flakes (if using) and cook for another minute until fragrant. Add the spinach and cook until wilted, about 3-5 minutes. Remove from heat and let cool slightly.

In a bowl, combine the cooked spinach mixture with feta cheese and mozzarella cheese. Mix well.

Preheat oven to 450°F (232°C). Line a baking sheet with parchment paper.

Punch down the dough and divide it into 4 equal pieces. On a lightly floured surface, roll each piece of dough into an oval shape, about 8-10 inches long and 4-5 inches wide.

Place the dough ovals onto the prepared baking sheet. Spread the spinach and cheese mixture evenly down the center of each oval, leaving a 1-inch border on all sides.

Pinch the ends of the dough together to form a boat shape, leaving the center open. Brush the edges of the dough with egg wash. Sprinkle with sesame seeds if desired.

Bake for 15-20 minutes, or until the crust is golden brown and the cheese is melted and bubbly. Let cool slightly before serving.

Slice and serve warm.