Thinly slice the flank steak against the grain into bite-sized strips.
In a small bowl, whisk together coconut aminos, water, arrowroot powder, minced ginger, and minced garlic to create the stir-fry sauce.
Heat a large skillet or wok over medium-high heat and add the toasted sesame oil.
Season the beef with sea salt and black pepper, then sear in the hot pan until browned, about 3-4 minutes.
Remove the beef from the pan and set aside; add the broccoli florets with a splash of water and cover for 2 minutes to steam until vibrant green.
Return the beef to the pan, pour the sauce over the mixture, and toss for 1 minute until the glaze thickens and coats everything beautifully.
Garnish with sesame seeds before serving.