Slow Cooker Pulled Pork Sandwiches

Bahan-bahan (8 porsi)

• 4 to 5 pounds boneless pork shoulder roast
• 8 to 12 hamburger buns (for serving)
• barbecue sauce (for serving, optional)
• 1 medium onion (chopped)
• ¾ cup apple cider vinegar
• ½ cup ketchup
• ½ cup chili sauce (like Heinz, or additional ketchup)
• ¼ cup brown sugar (firmly packed)
• ¼ cup molasses
• 1 tablespoon Worcestershire sauce
• 1 teaspoon dry mustard powder
• 1 teaspoon black pepper
• ½ cup mayonnaise
• 1 ½ tablespoons white vinegar (or apple cider vinegar)
• 2 teaspoons granulated sugar
• ½ teaspoon celery seed
• ⅛ teaspoon salt
• 5 cups coleslaw mix (or finely shredded cabbage)