Slice the beef flank steak against the grain into thin strips, then season evenly with sea salt and black pepper.
In a small bowl, whisk together the coconut aminos, toasted sesame oil, minced garlic, and grated fresh ginger.
Heat the avocado oil in a large skillet or wok over medium-high heat until it begins to shimmer.
Add the beef strips in a single layer and sear until beautifully browned, about 2 minutes per side, then remove the beef and set it aside.
Add the broccoli florets to the same pan with a small splash of water, cover with a lid, and steam for 3 minutes until tender-crisp.
Return the beef to the pan, pour in the prepared sauce mixture, and toss everything together for 1 minute until the glaze thickens and coats the ingredients.
Garnish the dish with sesame seeds and serve immediately while hot.