For a home cook–friendly version of this classic Japanese noodle stir-fry, we started by isolating the best possible supermarket alternatives to hard-to-find Japanese ingredients. In place of chewy yakisoba noodles, we use lo mein noodles (which also contain an alkaline ingredient that gives them some elasticity) and undercook them to enhance their chew. We also rinse them very well with cold water, which removes surface starches and makes them appropriately slick. We treat thinly sliced flank steak with baking soda to ensure that each piece is tender and juicy. Soy sauce, Worcestershire, ketchup, and rice wine vinegar make up the savory-sweet sauce—a facsimile of the traditional version made with Japanese Worcestershire sauce.