Thinly slice the flank steak against the grain into bite-sized strips and season with sea salt and black pepper.
In a small bowl, whisk together the coconut aminos, toasted sesame oil, grated ginger, and arrowroot powder to create the stir-fry 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 2-3 minutes until browned and caramelized, then remove from the pan and set aside.
Add the broccoli florets and sliced red bell pepper to the same pan with a splash of water, covering for 2 minutes to steam-tenderize.
Return the beef to the pan, add the minced garlic, and pour the sauce over the mixture.
Toss constantly for 1-2 minutes until the sauce thickens and glazes the ingredients beautifully.
Garnish with sesame seeds before serving.