Instruction

1. Pat roast dry using paper towels; sprinkle evenly with salt and pepper.
2. Heat oil in a large skillet over medium-high until shimmering. Add roast; cook until browned on all sides, 2 to 4 minutes per side, adjusting heat as needed to prevent overbrowning. Transfer roast to a 6-quart slow cooker.
3. Remove and discard drippings from skillet; add broth. Cook over medium, stirring constantly and scraping bottom of skillet using a wooden spoon, until browned bits are loosened, 1 to 2 minutes. Pour broth mixture over roast in slow cooker.
4. Stir together mayonnaise, 1 tablespoon of the peperoncini liquid, garlic powder, and dill in a small bowl until combined.
5. Spread mayonnaise mixture over top of roast; top with peppers and butter. Cover and cook until meat is fork tender, 6 to 8 hours on LOW. Transfer meat to a large bowl; loosely cover with aluminum foil.
6. Skim and discard fat from liquid in slow cooker using a ladle; stir in remaining 1 1/2 teaspoons peperoncini liquid. Whisk together cornstarch and water in a small bowl. Whisk cornstarch mixture into liquid in slow cooker, and transfer to a medium saucepan. Bring to a boil over medium, whisking often; cook, whisking often, until thickened, about 1 minute.
7. Shred meat in bowl, discarding any large fatty portions; stir in 1/2 cup liquid mixture, parsley, and chives. Season with salt to taste.
8. Divide egg noodles evenly among 6 bowls. Top evenly with meat and remaining liquid mixture. Garnish with parsley and chives.