Ingredients :

• The Beef — Rump steak, hanger steak, or sirloin—avoid stewing beef or shoulder at all costs; they are too fatty and take too long to tenderize for this type of quick cooking. Hanger steak is the best choice: reasonable price, bold flavor, and a firm texture that holds up perfectly to searing. Ask your butcher to slice it thinly if you want to make your life easier.
• Yellow Onions — Two large ones, sliced into thin half-moons of 3-4 mm max. Not red onions—they turn a weird color after cooking and their natural sweetness tips over into being too sugary too quickly. The classic yellow onion is ideal: it caramelizes cleanly, with that slight bitterness that balances the meat.
• Soy Sauce — Technically optional. In practice, it’s what brings that umami depth that you can’t quite name but notice immediately when it’s there. Kikkoman or any standard supermarket brand, one tablespoon, no more.
• Honey — One teaspoon to kickstart the onion caramelization. Honey provides a slightly floral base and caramelizes more gradually than white sugar. If you have maple syrup on hand, even better—it gives a superb amber color and a discreet fragrance that is a pleasant surprise.