Stir the potatoes, carrots, celery, soup and garlic in a 5-quart slow cooker. Season the beef with the black pepper. Add the beef to the cooker and turn to coat.
Cover and cook on LOW for 10 to 11 hours or until the beef is fork-tender. Sprinkle with the parsley, if desired.
For thicker gravy: Stir 1/4 cup all-purpose flour and 1/2 cup water in a small bowl until smooth. Remove the beef from the cooker. Stir in the flour mixture. Cover and cook on HIGH for 10 minutes or until the mixture boils and thickens.
Cooking Basics: True "baby" carrots are a seasonal vegetable available in spring and early summer and are sold in bunches with the green tops left on. They can usually be found in upscale grocery stores or farmers' markets. "Baby-cut" carrots are mature carrots that have been peeled and cut into small carrot-shaped pieces. They are widely available year round in the produce section of most grocery stores.