To make the burgers, combine the beef mince, chopped parsley, Fountain Steak Sauce, Fountain Mustard sauce, grated onion, egg and breadcrumbs in one bowl. Season with salt flakes and pepper, and form the mixture into four patties.
To make capsicum relish, heat olive oil in a pan over medium-high heat and sauté onion. Add red capsicum and cook until soft. Stir in Fountain Spicy Red Sauce and simmer until thickened.
Grill burgers on barbecue grill plate until cooked to your liking. Top each burger with a piece of sliced cheddar or Jarlsberg.
Place burgers on brioche buns and top with lettuce, tomato and Spicy Red Sauce or capsicum relish. Serve burgers with shoestring fries.