Add beef pattie to heated frying pan, season with salt and pepper.
Cook evenly on both sides (season again when turned over).
Add bacon to pan and cook on both sides until crispy and golden. Remove from pan and leave to drain on a lined plate.
Whilst meat is cooking begin to put together the sandwich. On non-buttered side spread sauces, add lettuce, one slice of cheese and onion. Once meat is rested add it to the sandwich and top with the pickles and the other slice of cheese, then place the other slice of bread on top.
While pan is still warm (keep on medium heat), lay sandwich to toast until lightly browned on both sides. Don’t rush this- you want to brown the butter so at least 3-4 minutes per side.
Serve while still warm with a side of French fries and a salted caramel shake for best results!