Preheat oven to 450°F and line a baking sheet with parchment paper. Make slices in each potato about 1/8 of an inch thick, taking care not to cut all the way through. You can place chopsticks or the handle of a wooden spoon on either side of the potato to keep your knife from going through, if needed. Microwave potatoes on high for 15 minutes. Cut cheese slices and ham into rectangles that will roughly fit in the slits. In between each slice in the potato, place a piece of cheese and a piece of ham. Place potatoes on baking sheet. In a small bowl, whisk together melted butter, Worcestershire sauce, mustard, onion powder, and salt and pepper. Brush over potatoes. Bake until cheese is melted and potatoes are golden brown, about 10 minutes. Sprinkle with fresh chives, serve, and enjoy!