Fry the Livar bacon in the pan and set aside. In the released frying fat, fry the abbey burgers until cooked. Fry the onion in the pan or chop onion and mix into the mince before frying. Place the onion on the burger together with the bacon or breakfast bacon. Top this with the cheddar and let it melt over the burger. Cut the brioche bun in half and place in the pan with the cut side down. Once the bread is toasted, spread the bottom with ketchup and the top with mustard. Then place a leaf of cabbage lettuce on the bottom and build up the burger. Finish with the tomato and pickle.