Heat large nonstick skillet over medium heat; add onions, carrots, green beans and corn, and cook 10 minutes, or until tender. Add ground beef and cook 10 minutes, or until cooked through. Add garlic, Worcestershire sauce, beef stock, cornstarch and simmer 10 minutes, or until most liquid evaporates.
Spoon veggie/meat mixture into 11x7-inch baking dish using slotted spoon. Layer potatoes on top, overlapping edges, and brush with oil, salt and pepper. Bake 30 minutes, or until potatoes are tender and browned. Top with cheese.