Swedish Meatball Burgers | Outback Barbecues

Ingredients

• 2 onions, sliced
• Vegetable oil, for cooking
• 250g minced beef
• 250g minced pork
• ½ onion, grated
• A small grating of nutmeg (around ½ teaspoon)
• ½ teaspoon ground cardamom
• 50ml milk
• 40g breadcrumbs
• ½ teaspoon white pepper
• 1 egg
• 25g butter
• 25g flour
• 250ml beef stock
• 2 tablespoons sour cream
• 4 cheese slices (we used Gouda)
• 4 buns, toasted