Place carrots, celery, onions, rosemary, thyme, garlic bulb and scallion in bottom of a 6-qt. CrockPot.
Scatter butter over the vegetables.
Salt and pepper the beef roast on both sides.
Lay on top of vegetables.
Mix broth, Worcestershire sauce and red wine together. Then pour mixture over ingredients in crock pot.
Cook on low for 6 hours.
Add potatoes to crock pot and cook on high an additional 2 hours.
Carefully remove roast. It should be so tender it falls off the bone.
Remove vegetables and keep all warm.
Discard the sprigs of rosemary, thyme, and garlic.
Strain juice and make gravy, if desired.
Make a rough and mix into the boiling broth, stir until thickened.