Add steak, soy sauce, baking soda, cornstarch and 2 tsp sesame oil to a small bowl. Toss to coat the steak and allow the beef to marinate while you are prepping the sauce and the broccoli.
Meanwhile, mix together all of the sauce ingredients in a medium bowl.
Add broccoli and 1 cup water to a large saute pan or wok. Bring to a boil and cook the broccoli for 2-3 minutes or until it's a bright green color. Immediately transfer the broccoli to a bowl with ice water.
Wipe out the pan the broccoli was cooked in and add in 1 tablespoon of oil to the pan. When pan is almost smoking add in beef. Sauté for 1-2 minutes on each side.
Toss in garlic and ginger and saute for 1 minute.
Add the broccoli back to the pan along with the sauce. Toss to coat the beef and the broccoli. Serve immediately with sesame seeds if desired.