Peel and cut potatoes into small cubes. Peel carrots; slice into thin rounds. Dice celery. Place all in Multipurpose Steamer; add 1⁄2 cup water. Cover; microwave on high for 8 min, or until veggies are tender.
Meanwhile, heat oil in Wok. Crumble in beef; cook, breaking up any clumps with the Ground Meat Separator, 4–5 min. Add remaining 2 cups water, soy sauce, and seasoning. Stir in veggies and any liquid in steamer.
Increase heat to high; cover, bring to a boil. Once it reaches a boil, uncover, reduce heat and let simmer to develop flavour, about 3 min.
Meanwhile, in a small bowl, whisk together cold water and cornstarch. Add to stew; stir often until thickened, about 2–3 min.