If making rice or noodles, start cooking them first. Prep all your stir fry ingredients in advance, as cooking goes quickly. Trim any excess fat from the flank steak and slice it thinly across the grain into bite-sized pieces.

In a bowl, combine the soy sauce, water, honey, grated ginger, minced garlic, vinegar, and red pepper flakes. Whisk together until well mixed and set aside.

In a large skillet, heat 1 tablespoon of olive oil over high heat. Let the pan heat for a few minutes until the oil shimmers. Add the sliced onion, broccoli florets, and red bell pepper. Cook for 4-5 minutes, stirring often, until the vegetables are tender-crisp. Transfer them to a plate and set aside.

Add the remaining tablespoon of olive oil to the skillet. Spread the sliced beef in a single layer and let it sit for one minute without stirring. Flip the beef and cook for another minute or so until it is nearly done. Aim to leave it slightly rare to avoid overcooking.

Return the cooked vegetables to the skillet with the beef. Pour in the prepared sauce and stir well to coat all ingredients. Cook for an additional 1-3 minutes until the sauce thickens and everything is heated through. Remove from heat and serve immediately over rice or noodles.