In a large bowl, combine the cubed round steak, onion, garlic, flour, salt, and pepper.
Heat the olive oil in a large skillet over medium-high heat. Add the round steak mixture and cook, stirring occasionally, for 5 minutes or until the beef is browned.
Transfer the round steak mixture to the slow cooker.
In a small bowl, whisk together the beef broth, Worcestershire sauce, ketchup, and mustard. Pour the mixture over the beef in the slow cooker.
Cover and cook on low for 8-10 hours or until the beef is tender.
In a small bowl, whisk together the cornstarch and cold water. Whisk into the slow cooker and stir gently to combine.
Cover and cook on high for 15 minutes or until the sauce is thickened.
Serve the round steak and gravy over mashed potatoes or rice.
Interesting Facts
Round steak is a lean cut of meat that is best cooked slowly over low heat.
The gravy created by this slow-cooker round steak is full of flavor and perfect for pouring over mashed potatoes or rice.
This recipe is a great way to use up any leftovers, as the round steak can be easily shredded and added to the gravy.