Remove the burgers from the fridge thirty minutes before cooking to allow the meat to temper
Make the burger sauce by finely mincing the onion and then mixing it into all the other sauce ingredients until well combined
Bring a non-stick or cast iron pan to a high heat – the pan should be almost smoking
Season the burgers well with salt and black pepper
Place the burgers in the pan and hard sear for two to three minutes to form a dark, charred crust on one side of the burgers
Flip the burgers and reduce the heat to medium low
Place a slice of Swiss cheese on top of each burger and allow to cook for a further three to five minutes until they've reached your required level of done-ness and the cheese has melted onto the top of the burgers
Remove the burgers from the pan and allow to rest for two minutes
While the burgers rest, turn the pan to low and toast off your burger buns, and warm the sauerkraut slightly
To assemble, spread some of the sauce on each side of your toasted buns
Lay the sauerkraut on the bottom half of the buns, top with the burgers, lay on the gherkins, and finally crown with the top half of the bun
Serve with fries, onion rings, and a side of dressed salad
