Heat oil in a large skillet over medium-high heat. Add roast and brown on all sides, then transfer to a slow cooker.

Sprinkle onion soup mix over roast, then pour in apple juice. Cover and cook on Medium until meat is very tender, 6 to 8 hours, checking occasionally to make sure there is sufficient liquid and adding more apple juice if necessary.

Serve roast with cooking juices, or thicken the juices for a tasty gravy.