Prep everything ahead of time as the actual cooking part goes very quickly. To prep the steak, trim off any fat and slice it across the grain into thin bite-size pieces. Add the sauce ingredients to a bowl and whisk together thoroughly.

Add 1 tablespoon of the olive oil to a large skillet over high heat. Let the pan heat up for a few minutes (oil should be shimmering).

Add the broccoli and cook for 4-5 minutes, tossing/stirring often (it'll be tender-crisp). Transfer it to a plate or bowl.

Add the remaining tablespoon of olive oil to the skillet. Add the beef in a single layer (just sort of "sprinkle" it into the pan ensuring it's spread out a bit) and don't touch it for a minute. Stir/flip it with cooking tongs and cook it for another minute or so. It cooks fast and will easily overcook and become tough. Leaving it a bit rare at this stage is ideal.

Add the broccoli back to the pan and pour the sauce in. Stir/toss until coated and the sauce has thickened (about 1-3 minutes). Take the skillet off the heat and serve immediately. Top with sesame seeds for aesthetics! Serve by itself or on top of rice.