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