1. In a large bowl mix together the beef mince, garlic granules, onion salt, black pepper and Worcestershire sauce until fully combined.
2. Divide the mixture into 4 and shape each patty into a 6 inch thin circle. Stack 4 slices of Castello Jalapeño Havarti on top of each other.
3. Slice the cheese into 4 pieces and keep them together, take one quarter and place it in the center of a patty. Press a second patty on top to seal the cheese between the two patties.
4. Preheat the grill to high.
5. Cook the cheese-filled patty on a grill pan for 6-7 minutes on each side. Place a slice of Castello Jalapeño Havarti on top of each burger and cover with a metal cloche for 2-3 minutes until melted.
6. Add vegetable oil into a medium frying pan and cook the sliced onions over a low heat for 10 minutes until softened. Add in the maple syrup and vinegar. Cook for 20-25 minutes over a low heat, stirring occasionally, until caramelized.
7. Place the bacon in grill pan and cook until crispy for 5 mins.
8. Serve the burger straight away, inside a toasted brioche bun, topped with the caramelized onions, crispy bacon and garnished with some sliced jalapeño and arugula.