Prepare the homemade burger sauce by mixing together the tomato ketchup, mayonnaise and Worcestershire Sauce. Set aside.
Place a large frying pan on a medium heat and add the oil. Once hot, fry the patties for 6-8 minutes one each side, or until cooked. Place a slice of Dubliner Original White on top of each patty and cook until melted. Remove the patties from the pan.
Place the brioche burger buns, cut side down into the pan and toast for 1 minute.
To assemble the burgers, spread burger sauce on the bottom of the burger bun. Top with sliced lettuce and tomato. Top with burger, red onion and gherkins. Spread top of the bun with burger sauce and place on top to finish. Repeat with the remaining burgers.