Smoky Pulled Pork Sandwiches

Ingredients

• 1 bone-in pork shoulder roast, about 6 to 7 lb. (3 to 3.5 kg)
• Kosher salt and freshly ground pepper
• 1 jar Kansas City barbecue sauce
• 8 hamburger buns, split and toasted
• Pickle slices for serving (optional)
• 2 Tbs. canola oil
• 1/2 cup (4 fl. oz./125 ml) white wine vinegar
• 1/4 cup (2 oz./60 g) sugar
• 1 garlic clove, minced
• 2 Tbs. whole-grain mustard
• 1 tsp. celery seed
• Kosher salt
• 1/2 head green cabbage, cored, halved and thinly sliced
• 1/2 head  purple cabbage, cored, halved and thinly sliced
• 2 carrots, peeled and julienned