For the Pork:
1 whole pork butt, 5 to 6 pounds
1 tablespoon liquid smoke
2 tablespoons soy sauce
1 cup water
For the Slaw:
1 small head purple cabbage, cored and thinly sliced
1 small onion, peeled and thinly sliced
1 tablespoon sesame oil
1/2 tablespoon rice wine vinegar
Freshly ground black pepper
1 package Hawaiian bread rolls
For the Pork: Place pork in slow cooker and pierce all over with a fork. Rub with salt, liquid smoke, and soy sauce. Add water. Cover and cook on low for 18 hours, turning once.
For the Slaw: Combine cabbage, onion, sesame oil, and vinegar. Season with salt and pepper. Stir to combine and refrigerate until ready to use, at least one hour and up to overnight.
Remove pork from the slow cooker and shred meat. Mix with juices to moisten and season to taste with salt and pepper. Serve pork tucked into rolls, topped with slaw.