1. Make the Dough (If Using Homemade Dough):

• In a large bowl, combine the flour and salt. Add the cold butter and use a pastry cutter or your fingers to rub the butter into the flour until the mixture resembles coarse crumbs.
• Gradually add the cold water, 1 tablespoon at a time, until the dough comes together. Add vinegar if desired.
• Turn the dough out onto a floured surface and knead gently to form a smooth ball. Wrap in plastic wrap and chill for at least 30 minutes.

2. Prepare the Filling:

• Heat the olive oil or butter in a large skillet over medium heat. Add the chopped onion and cook until softened, about 4-5 minutes.
• Add the garlic and cook for another 1 minute, until fragrant.
• Stir in the sliced mushrooms and cook for about 8-10 minutes, stirring occasionally, until the mushrooms release their moisture and become browned. The mushrooms should shrink and soften.
• If using, add the tomato paste, cumin, smoked paprika, salt, and pepper, and cook for another 2 minutes. Stir in fresh parsley if desired. Remove from heat and allow the filling to cool slightly.

3. Assemble the Empanadas:

• If using homemade dough, roll it out on a floured surface to about 1/8 inch thickness. Use a round cutter (about 4-5 inches in diameter) to cut out circles. If you’re using store-bought dough (like empanada discs), simply place the discs on a flat surface.
• Place about 1-2 tablespoons of the mushroom filling in the center of each dough circle.
• Fold the dough over to form a half-moon shape, pinching the edges together to seal the empanada. You can crimp the edges with a fork to make a decorative seal, if desired.
• Brush the top of each empanada with the beaten egg to give them a golden, glossy finish when baked or fried.

4. Cook the Empanadas:

• To Bake:

  • Preheat your oven to 375°F (190°C).
  • Place the empanadas on a baking sheet lined with parchment paper.
  • Bake for 20-25 minutes, or until the empanadas are golden brown and crispy.

• To Fry:

  • Heat about 1-2 inches of vegetable oil in a deep pan or skillet over medium heat.
  • Fry the empanadas in batches for 2-3 minutes per side, or until golden brown and crispy. Use a slotted spoon to remove them and place them on paper towels to drain excess oil.

5. Serve:

• Allow the empanadas to cool slightly before serving. These are great on their own or with a dipping sauce such as chimichurri, a spicy salsa, or sour cream.