This is an easy slow cooker beef stew made with tomato soup. The stewing beef is combined with tomato soup, potatoes, and carrots, along with seasonings. Feel free to vary the ingredients with the vegetables you have on hand. Add onions and root vegetables with the beef, but wait until about 20 to 30 minutes before it's done to add any frozen vegetables to prevent overcooking. I recommend round white potatoes or red-skinned potatoes for stews. Starchier baking potatoes tend to break down over the long, slow cooking time.