Make sure your veggies are chopped and prepared before starting.
Heat 1 tablespoon of oil in a large pan over medium heat. Add the beef strips and brown on both sides, about 3 minutes each. Remove from the pan and set aside.
Add the other tablespoon of oil and add the broccoli and green beans. Let cook for 5-7 min, until they become more colorful and slightly softer.
While the broccoli and green beans are cooking, mix the coconut aminos, ginger, and apple cider vinegar together.
Add the aminos mixture to the pan then add in the water chestnuts. Stir to combine and cook for 5 min. Next, add the mushrooms and cook for another 3 minutes, stirring occasionally.
Add the beef back in and mix well. Cook for about another 10 minutes, mixing occasionally, until beef is done.
Let rest for 5 minutes before serving. Serve and sprinkle with sesame seeds if desired.