Place the chuck roast in the crock pot. Season generously with salt and pepper. Place the onions and celery on top. Whisk together the ketchup, vinegar, water, seasonings(oregano, garlic powder, Italian seasoning), worchestershire sauce, and chili sauce and pour over the beef
Cook on low for 7- 8 hours until the beef is tender. You can cook on high for 3-4 hours, but I highly recommend cooking on low, if possible. This will yield the most tender meat. Check your roast at 7 hours. If it shreds easily, it's ready! If not, continue cooking another hour.
Using the meat claws or two forks, shred the beef and return it to the pot and mix with the juices. Serve the shredded beef on buns with a slice of provolone cheese
