Season chuck roast on all sides with salt. Let rest in the fridge for 4+ hours
Season chuck roast on all sides with a low sodium all purpose seasoning and pepper
Add 2-3 tablespoon avocado oil(or any high smoke point oil) to skillet/Dutch oven and sear both sides of roast for 2-3 minutes
Add in your onion slices to the bottom of a slow cooker/dutch oven
Add your chuck roast to a slow cooker/dutch over on top of your sliced onions
Add in ranch packet to the top of your roast
Add in au jus packet to the top of your roast
Add in 8-10 or so pepperoncini (remove stems) and some of the juice
Top with a stick of butter
Cook for low for 6 hours or high for 4 hours (if used a dutch oven, place in the oven on around 250 for 4 hours or until meat shreds easily).
Once done, remove your roast from the juices and shred using 2 forks in a large bowl or plate
Add your shredded roast back into your gravy and mix thoroughly
Serve over rice or mashed potatoes