Preheat a pan over medium heat and cook bacon until crisp. Toast bread slices and cover with sandwich sauce. Mix lettuce with mayonnaise.
Layer an egg, some tomato slices and a bit of the lettuce mixture on one slice of bread then top with another slice of bread.
Add the chicken and bacon. Finish with the final slice of bread. Cut sandwich into quarters. Secure with cocktail sticks and serve with potato crisps and shallot pickle.