Cheeseburger-flavored empanada

Ingredients:

• 0.5 cups ketchup
• 0.5 cup mayonnaise
• 0.5 cup chopped pickles + 18 whole slices of pickles
• 1/4 cup mustard
• 1 tbsp. l. rapeseed oil
• 240 g of ground beef shoulder
• Half a small red onion, finely chopped
• 4 slices cheese, coarsely chopped
• 1 large egg
• 0.5 kg frozen puff pastry (2 sheets), defrosted
• Flour for work
• Special equipment: round cookie cutter with a diameter of 10 cm.

Preparation:

1. Position 2 oven racks on the middle shelf and preheat the oven to 220°C. Line 2 large baking sheets with parchment paper.
2. In a medium bowl, combine ketchup, mayonnaise, finely chopped pickles, and mustard. Season with salt.
3. Heat the oil in a large skillet over medium-high heat. When it shimmers, add the ground beef, a pinch of salt, and a few grinds of pepper. Cook, breaking up the ground beef with a wooden spoon or spatula, until cooked through and lightly browned in spots, 3 to 4 minutes. Add the onion and cook, stirring constantly, until crisp-tender, about 2 minutes. Using a large slotted spoon, transfer the ground beef to a medium bowl and toss with 1/3 cup of the sauce. Let cool slightly. Stir in the cheese.
4. Prepare the egg wash by lightly whisking the egg with 1 tablespoon water in a small bowl.
5. Place 1 sheet of puff pastry on a lightly floured surface. Roll it out into a 30cm square. Using a 10cm cookie cutter, cut out 9 circles from the dough. Place 1 level tablespoon of meat filling in the center of each circle. Place 1 slice of pickle on top of the meat. Brush the edges of each circle with the egg mixture and fold the dough into a crescent shape, stretching it slightly if necessary. Press the edges together and crimp them with a fork. Place on one of the prepared baking sheets and brush each empanada with the egg mixture. Repeat with the remaining sheet of puff pastry and filling. Bake until golden brown, about 15 minutes. Serve the empanadas hot with the remaining sauce.