To cook roast beef in a slow cooker, follow these general steps:

1. Season the beef roast with salt, pepper, and preferred seasonings. Optionally, rub with steak and Italian seasonings.
2. Sear the roast in a hot skillet with some oil for a few minutes on each side to brown and lock in flavor.
3. Place chopped vegetables like carrots, potatoes, onions, and celery at the bottom of the slow cooker.
4. Put the seared roast on top of the vegetables in the slow cooker.
5. Add beef broth and optionally some red wine or a soup mix for flavor. The liquid should cover the vegetables and part of the roast.
6. Cover and cook on low for 8-10 hours or on high for 4-6 hours until the beef is tender.
7. Once cooked, remove the roast and let it rest briefly. Use two forks to shred or slice the meat.
8. Optionally, prepare gravy by thickening the cooking liquid with cornstarch mixed with water, heated until thickened.
9. Serve the roast beef with the cooked vegetables and gravy.

This method yields a tender, juicy roast with flavorful vegetables and gravy, great for a comforting meal.