Season the Double Angus Burgers, then cook frozen, at high heat for approx. 18 minutes (core temperature 69°C), repeatedly turning.
Mix mayonnaise, mustard and sour cream and season to taste.
Slice burger bun horizontally and toast.
Burger stacking order: brioche-bun-bottom, ketchup, lettuce, Angus Burger patty, tomato slices, Gouda, Angus Burger patty, lettuce, mustardcream, brioche-bun-lid