Brown roast in hot oil in a skillet over medium-high heat 3 to 5 minutes on each side; transfer to a 6-qt. slow cooker. Whisk together beer and dressing mix; pour over roast. Cover; cook on LOW 8 to 10 hours or until tender. Remove roast from slow cooker. Skim fat from sauce; serve with roast.
I shred roast in sauce and serve in buns; added a little coarse ground pepper.