Heat oil in a large Dutch oven over medium-high heat. Add half of the beef; cook 5 minutes or until browned, turning occasionally. Remove from pan. Repeat procedure with remaining beef. Add leek and mushrooms to pan; sauté 3 minutes. Return beef to pan; stir in carrot and next 6 ingredients (carrot through beer). Bring to a boil; cover, reduce heat, and simmer 2 hours or until beef is tender.
Combine cornstarch and vinegar in a small bowl. Add cornstarch mixture to beef mixture; bring to a boil. Cook 3 minutes, stirring constantly.