Slow Cooker Beef, Barley, and Mushroom Stew

Place potatoes in a large pot and cover with water. Bring to a boil. Reduce heat and simmer until they're almost falling apart, about 20 minutes.

While potatoes are cooking, heat olive oil in a medium pan over medium-high heat. Add steak and brown on all sides, 5 to 7 minutes total.

Pour beef broth and condensed soup into the bottom of a slow cooker and set to Low. Add barley. Drain potatoes and add to the cooker. Add steak, including pan juices and oil, followed by onion, mushrooms, garlic, oregano, salt, and pepper.

Cover and cook on High for 1 hour. Add frozen vegetables and continue to cook until barley and vegetables are tender and steak is cooked through, about 2 hours more.