Cheeseburgers with chopped filling

Ingredients:

• 1 tbsp. vegetable oil
• Half an onion, finely chopped
• 600 g ground beef, broken into pieces
• 2-4 tbsp chopped pickled hot peppers
• 8 slices cheese (approximately 110 g)
• 1/3 cup mayonnaise
• 4 soft long buns, cut in half and toasted
• Shredded iceberg lettuce, tomato slices, ketchup and hot sauce, for assembly
• Potato chips, for serving

Preparation:

1. Heat a large cast-iron skillet over medium-high heat. Add the vegetable oil, then add the onion, ground beef, 1/2 teaspoon salt, and some freshly ground black pepper. Cook, undisturbed, until the beef begins to brown, 1 to 2 minutes. Turn with a spatula, breaking up the ground beef. Continue cooking until the ground beef is golden brown, about 30 seconds more. Add the pickled peppers, then arrange the cheese on top of the meat mixture. Remove from the heat and let the cheese melt.
2. Spread mayonnaise on both sides of the buns. Use a spatula to spread the beef onto the bottom halves of the buns. Top with lettuce, tomatoes, ketchup, and hot sauce, and cover with the bun tops. Serve with potato chips.