Rub roast all over with salt and pepper and place into a slow cooker. Place the butter on top of the roast and the pepperoncinis around it. Carefully pour the beef broth around the roast, and not over the top. Cover with the lid.
Cook on low for 8-10 hours, or on high for 5-7 hours.
Shred meat into chunks and serve with rice or mashed potatoes, spooning the juices over the top. Or, stuff into tacos or burritos.
Save the juices from your slow cooker to make gravy.
Want it spicier? Try add a couple of jalapenos instead of pepperoncinis.
Feel free to add in some fresh garlic and onion for added flavor.
Add some root veggies, like potatoes and carrots, to bulk up your meal.