Begin by slicing the flank steak against the grain into thin strips. This helps keep the meat tender. Chop the broccoli into bite-sized pieces and slice the green onions. Mince the garlic and grate the ginger. Get all your ingredients prepped; it makes the cooking process smoother.

In a medium bowl, mix the beef with tapioca starch, hoisin sauce, and rice vinegar. Allow it to marinate for about 10-15 minutes. This step is crucial. It not only flavors the beef but also helps to tenderize it.

In a large skillet or wok, heat the olive oil over medium-high heat. The pan should be nice and hot to get a good sear on the meat.

Add the marinated beef to the skillet in a single layer. Let it cook for a few minutes until one side is browned. Flip it to cook the other side. This usually takes about 3-4 minutes in total. Remove the beef from the pan and set it aside.

In the same pan, toss in the broccoli and a splash of water or broth. Cover for a couple of minutes to steam the broccoli slightly. You want it bright green and tender-crisp.

Once the broccoli is cooked, add the beef back to the pan. Pour in the soy sauce, honey, garlic, and ginger mixture. Stir everything together well, letting it simmer for a couple of minutes so the flavors meld.

Serve your healthy Mongolian beef over quinoa or your choice of rice. Sprinkle with sliced green onions and your optional toppings.