Pat the flank steak dry with a paper towel and slice it against the grain into very thin strips.
Season the beef strips evenly with the sea salt and black pepper.
In a small glass bowl, whisk together the coconut aminos, minced garlic, and grated ginger root to create the stir-fry sauce.
Heat the avocado oil in a large skillet or wok over high heat until it begins to shimmer.
Add the beef to the skillet in a single layer and sear for 2 minutes until browned and caramelized, then remove the beef and set it aside on a plate.
Add the broccoli florets to the same skillet with one tablespoon of water, covering with a lid for 2 minutes to steam until they are vibrant green and tender-crisp.
Return the beef and any accumulated juices to the pan, pour in the sauce mixture, and toss everything together for 1 minute until the sauce thickens and coats the ingredients.
Remove from the heat, drizzle with the toasted sesame oil, and garnish with sesame seeds before serving immediately.