Heat up your smoker to 225-250 degrees. Once it comes up to temp, add your favorite wood (I like post oak). If you are using a Big Green Egg, use a platesetter. 

Season the chuck roast all over with your rub of choice. Put it on the smoker and let cook for about two hours until it develops a nice bark and is brown all over. Temp should be around 165 degrees.

Remove the meat and then, in an aluminum pan or dutch oven, add in the chuck roast, sliced onion, pepperoncini, ranch seasoning, beef broth and butter (sliced into cubes).

Cover with foil (or a lid) and cook until the meat is probe tender (meaning a temperature probe slides easily into the meat like butter). The meat should temp around 200 degrees but this will vary slightly between roasts so pull it when the probe slides in very easily. If you can shred some of it by twisting with a fork, that’s a good way to see if it’s done as well.

Remove from the smoker and transfer to a plate to rest for 10 minutes. Shred. You can add it back to the drippings or serve those on the side.