Preheat oven to 450°. Spread butter evenly on one side of bread and toast for 3-4 minutes, or until golden brown.
Remove from oven, turn the bread over, and spread another thin layer of butter. Toast for another 3-4 minutes.
Spread a thin layer of Dijon mustard on each slice of bread. Top with shredded cheese, 2 slices of ham, and apple slices. Add a little more cheese to help hold it all together. Put back in the oven for another 6-7 minutes, or until the cheese is melted and the bread is toasted and golden brown.
Grind black pepper over each piece of toast. Add a handful of arugula and a generous drizzle of hot honey.