Thinly slice each Qukes®, lengthways into four even slices. Place four slices of bread on a clean board. Spread evenly with avocado. Top each slice with half the Qukes®. Top with another four slices of bread. Spread evenly with chicken mixture.
Spread the remaining bread slices with butter. Place on top of the chicken mixture, buttered-side down. Spread tops with remaining mayonnaise (1 tablespoon on each). Arrange the remaining Qukes® over the top of each sandwich. Using a serrated knife, remove the crusts. Cut each sandwich in half and serve.