Spread a small amount of honey mustard on each piece of bread. Layer the chicken, apples and cheese on top of four pieces of bread. Top with remaining bread slices. Spread butter on the outside of each sandwich
Cook in a panini grill or on the stovetop until golden brown and cheese is melted. (To cook on stovetop: heat a non-stick skillet over medium low heat. Brown sandwiches on one side. Flip. Place a heavy plate on top of panini’s and press down lightly. Leave plate on top until other side is golden brown.)