Heat K&N's Mortadella Slices as per instructions given on the pack and set aside.
Lightly toast bread slices.
Combine the mayonnaise, mustard paste, salt and pepper in a bowl. Spread 1 tbsp of this mixture on 2 slices of bread, leave the third slice.
Layer lettuce, 4 tomato slices and 2 Mortadella Slices on the first slice of bread. Place plain slice of the bread on top.
Layer this plain slice of bread with lettuce, 4 tomato slices, fried egg, cheese slice and the remaining 2 Mortadella Slices.
Cover with the third slice of bread with mustard-mayonnaise mixture and place it on top of the sandwich, with mixture side facing down.
Secure the sandwich with 4 cocktail swords or food picks, about 1 inch from the sides. Slice sandwich into quarters, making 4 small triangle sandwiches.
Serve with coleslaw or potato salad and fries.