Truff Meatball Hoagie with Southern Buttermilk Slaw

Name: Truff Meatball Hoagie with Southern Buttermilk Slaw
Ingredients: 1 pound Ground Beef; ½ pound Ground Pork; ¼ cup Truff Sauce; ½ cup Panko Breadcrumbs; ¼ small White Onion, finely chopped; 1 Egg; ¼ cup freshly grated Parmigiano Reggiano; ¼ cup finely chopped Fresh Parsley; 1 tsp. Garlic Poweder; 1 tsp. Fresh Cracked Black pepper; ¼ cup Buttermilk; ¼ cup Mayonnaise; 1 tbsp. Granulated Sugar; ½ tsp. Celery Salt; Dash Freshly Ground Black Pepper; 8 ounces Shredded Coleslaw Mix; 2 Hoagie Rolls, toasted; Truff Sauce, for garnish; Chopped Chives, for garnish