Ingredients

· 500 g beef mince

· 1 brown onion

· 1/3 cup breadcrumbs

· 1 egg yolk

· 1 tablespoon mustard

· 150 g mozzarella cheese

· 1 tablespoon olive oil

· 4 brioche burger buns

· 2 tomatoes, green oak lettuce leaves and pickled jalapenos, to serve

For the Burger Sauce

· ¾ cup mayonnaise

· 2 pickled cucumbers

· 3 teaspoons mustard

· 1 teaspoon onion powder

· ½ teaspoon garlic salt

· ¼ teaspoon smoked paprika

· Salt and pepper

Method

To make the sauce, combine all ingredients in a jug. Season with salt and pepper. Mix well and set aside. Preheat grill to high heat. Divide mozzarella into four even thick square slices. Set aside. Combine mince, onion, egg yolk, breadcrumbs and mustard in a bowl. Season with salt and pepper. Divide the mixture into four equal portions. Shape portions into patties. Heat the oil in a frying pan over medium heat. Add the patties. Cook for five minutes on each side. Top the patties with mozzarella slices. Cover the pan with lid. Cook until cheese has melted. Remove patties from pan. Meanwhile, split rolls in half. Place cut-side up on an oven tray. Grill for two minutes until lightly toasted. Remove. To assemble, spread each bun base and top with a tablespoon of the sauce. Top bases with lettuce, tomato, patties and jalapenos. Serve with remaining sauce.