Rub the pork all over with seasoned salt and paprika. Heat the oil in a large, nonstick skillet over medium-high heat. Brown the pork on all sides, about 12 minutes.
PREPARE THE SAUCE:
Heat the oil in a large saucepan over medium-heat. Add the onion and cook 5 minutes. Stir in the vinegar, ketchup, brown sugar and mustard. Bring to a boil, then reduce heat and simmer 5 minutes.
SLOW COOK:
Transfer the pork to your slow cooker and pour the sauce on top. Cover and cook on HIGH for 6 hours or LOW for 8 hours.
PREPARE SLAW:
In a medium bowl, whisk together the mayonnaise, vinegar, sugar, celery salt and pepper. Stir in the coleslaw mix. Refrigerate until ready to serve.
SERVING:
Remove the pork from the slow cooker, place it on a cutting board. Meanwhile, stir in 1 tablespoon of cornstarch to the sauce in the slow cooker, put the lid on and turn the heat to high. Let it heat for about 15 minutes. With 2 forks (or with clean hands), shred the meat, discarding any fat or bones. Add the shredded meat back to the sauce in the slow cooker. Divide the meat evenly among the sandwich buns, topping with cole slaw, if desired.
Notes
*Tip on browning- use a cast iron skillet or a metal pan if you can (vs. a nonstick skillet). You'll get a nice sear all the way around your roast, sealing in the juices. Using a nonstick skillet, you won't get that nice brown sear.
*If you serve this pulled pork on slider buns instead of sandwich buns, you should get about 16 sliders out of the recipe.