In a mixing bowl, combine the diced ham, shredded Swiss cheese, and Dijon mustard. Add salt and pepper to taste and whisk until combined. Set aside., In another mixing bowl, combine the ground chicken, breadcrumbs, grated Parmesan cheese, beaten egg, garlic powder, onion powder, and salt and pepper. Mix until fully incorporated., Take a portion of the chicken mixture, flatten it slightly, place a teaspoon of the filling in the center, and fold the meat around the filling to form a ball. Repeat until all meatballs are formed., Preheat the oven to 400°F (200°C) and place the meatballs on a baking sheet lined with parchment paper. Bake for 20-25 minutes until golden brown and cooked through (internal temperature of 165°F/74°C)., While the meatballs are baking, whisk together the mayonnaise, Dijon mustard, lemon juice, and Worcestershire sauce in a mixing bowl until creamy. Season with salt and pepper to taste and add a dash of paprika., Once the meatballs are done, let them cool for a few minutes, then arrange them on a serving platter. Drizzle with sauce or serve it on the side.