Apple Jack Pulled Pork Buns

Name: Apple Jack Pulled Pork Buns
Ingredients: 2.5 pounds pork shoulder roast; 1 red onion, diced; 6 cloves garlic, minced; 2.5 teaspoons kosher salt; 1 teaspoon freshly ground black pepper; 1 teaspoon smoked paprika; 1 pinch cayenne pepper; 0.333 cup bourbon whiskey; 0.25 cup apple cider vinegar; 3 cups apple juice; 1 tablespoon chopped fresh chives, or to taste; 8 sesame seed burger buns; 4 cups finely shredded Savoy cabbage; 0.667 cup thinly sliced green bell pepper; 2 tablespoons thinly sliced green onions; 2 tablespoons prepared yellow mustard, or to taste; 2 tablespoons mayonnaise; 1 tablespoon apple cider vinegar; 0.5 teaspoon salt, or to taste; freshly ground black pepper to taste; 1 pinch cayenne pepper, or to taste