Mix crushed dried rosemary, sage garlic powder, paprika, dry mustard, celery salt and black pepper in a small bowl.

Trim and dry roast and coat with herb mixture, pressing it into the meat.

Heat olive oil over medium-high heat in a dutch oven or skillet. Once hot, add roast and sear each side for 2 - 3 minutes. Transfer to slow cooker.

Add beef broth and beer to cover meat. If any of the roast is still exposed add more beef broth until it is covered entirely.

Chop onion and celery and add to slow cooker along with potatoes and rosemary sprigs.

Cook on low for low for 6 - 7 hours, roast should be falling apart and easy to shred with a fork when done.

To make the gravy, remove roast and set aside. Strain the cooking juices into a sauce pan.

Simmer the juices over medium heat on stovetop. Whisk cornstarch with a little water and gradually whisk into the juices until thickened.

To serve immediately, shred or shave pot roast and place on slider buns; drizzle gravy over roast. To serve the next day, place shredded or shaved pot roast in a container and top with gravy. When ready to serve, add cold or reheated pot roast to slider buns.