To make the rosti, combine the grated Maris Piper, the egg yolk, flour, shallot and seasoning and shape into 2 patties
Cook in a large, roomy frying pan with a splash of vegetable oil over a medium heat for approximately 5 minutes or until each side is crispy. Set aside on paper towel.
To make burger mayonnaise, combine the mayo with the dill and capers, and chill.
Bake the bacon at about 200 degrees until crisp – approx. 8 minutes
Thoroughly cook burgers until juices run clear (barbecue, grill or pan). Add Applewood smoked Cheddar to the top of the patty for the last couple of minutes to allow it to melt.
Briefly toast the bun before smothering base with burger mayo, top with onion and lettuce – then layer in the following order – 1 x rosti, patty with melted cheese, bacon, gherkin slices, American mustard, final rosti and then finish with the top of the bun.