Heat a large frying pan or griddle, rub the oil over the burgers and season with sea salt and pepper then cook in the pan for 3 to 4 minutes on each side until cooked through. Add a slice of cheese to each burger and cover the pan with a lid to create some steam so the cheese will melt or pop under a hot grill to melt.
Grill the bacon until crisp and toast the buns.
Spread the bottom of each bun with the cranberry relish then add some lettuce and top with the burger and cheese. Add the bacon, top with the bun and serve immediately.