Add salt, pepper, and garlic powder to a small bowl and combine. Set aside.

Place chuck roast on baking sheet. Sprinkle seasoning on all sides of roast and rub in thoroughly and evenly. Transfer chuck roast to slow cooker.

Chop garlic and slice onion and arrange on top of chuck roast. In medium bowl, combine mushroom soup, Worcestershire sauce, and beef broth. Pour over chuck roast. It is ok if onion and garlic fall off chuck roast. Flavors will still combine while cooking.

Cook on low for 8-10 hours. Then remove from slow cooker and serve.