1. Prepare the Dough

• In a small bowl, dissolve the sugar and yeast in the warm water. Let it rest for 5-10 minutes until bubbly.
• In a large mixing bowl, whisk together the flour and salt. Create a well in the center and pour in the yeast mixture.
• Mix until a dough forms, then transfer to a floured surface.
• Knead the dough for 10 minutes until smooth and elastic.
• Place the dough in a lightly greased bowl, cover with a damp cloth, and let it rise for 1-2 hours, or until doubled in size.

2. Prepare the Filling

• Heat a small amount of oil in a skillet over medium heat.
• Sauté the onion until soft and translucent, about 3-4 minutes.
• Add the chopped spinach and cook until wilted, allowing any excess liquid to evaporate.
• Season with salt and red pepper flakes. Remove from heat and let cool completely.

3. Roll Out the Dough

• Punch down the risen dough and divide it into equal portions.
• Mix the all-purpose flour and cornstarch in a small bowl for dusting.
• Roll out each dough portion on a floured surface to about 1/8 inch thickness, forming circles or rectangles.

4. Assemble the Pastries

• Place a spoonful of spinach filling in the center of each dough piece.
• Fold the dough over the filling to form pockets, sealing the edges tightly. You can shape them into triangles, rectangles, or any preferred shape.
• Brush each pastry with the melted butter for a golden, flaky finish.

5. Bake the Pastries

• Preheat your oven to 375°F (190°C).
• Arrange the pastries on a baking sheet lined with parchment paper, leaving space between each.
• Bake for 20-25 minutes, or until golden brown and crispy.

6. Serve and Enjoy

• Remove the pastries from the oven and allow them to cool slightly.
• Serve warm or at room temperature as a delicious snack or appetizer.