Heat oil in large saucepan over medium-high heat. Working in batches, add beef; sauté until browned, about 4 minutes per batch. As beef browns, remove it to a pie plate or bowl.
Return all beef to saucepan. Stir in beef broth, barley and 5 cups water. Bring to boiling. Cover; simmer for 10 minutes or until barley is tender.
Stir in frozen mixed vegetables; gently heat through. Season with salt and pepper to taste. Makes 4 servings.