Trim excess fat from beef. Heat oil in 10-inch skillet over medium-high heat. Cook beef in oil about 10 minutes, turning occasionally, until brown on all sides. Sprinkle with salt and pepper.
Place onions in 3 1/2- to 6-quart slow cooker. Place beef on onions.
Mix remaining ingredients; pour over beef and onions. Cover and cook on low heat setting 8 to 10 hours or until beef is tender.
Remove beef and onions from cooker, using slotted spoon. Cut beef into slices. Skim fat from beef juices in cooker if desired. Serve beef with juices.
Note: This recipe was tested in slow cookers with heating elements in the side and bottom of the cooker, not in cookers that stand only on a heated base. For slow cookers with just a heated base, follow the manufacturer’s directions for layering ingredients and choosing a temperature.