Heat 4-5 tablespoons of olive oil in a large cast-iron skillet (any skillet) over medium-high heat.
Sear the outside of the roast until golden brown on all sides.
Place the seared roast directly into the crock pot.
Sprinkle the au jus seasoning and the ranch seasoning over the top of the roast.
Place the sliced or cubed stick of butter into the crock pot.
Pour in the entire jar of pepperoncinis. Make sure to include all the juice and all the peppers.
Add in optional veggies and potatoes. I used carrots and baby golden potatoes. Oh, and some leftover celery.
Cook on low for 8 hours (best results) or on high for 5 hours. Low and slow really gets it nice and tender.
After 8 hours, the meat will be nice and tender. Shred it with forks or meat scissors and then make sure it is all stirred around in the cooking juices.