Slice the flank steak against the grain into thin strips and season evenly with sea salt and black pepper.
In a small glass bowl, whisk together the coconut aminos, toasted sesame oil, minced garlic, and grated fresh ginger to create the glaze.
Heat the avocado oil in a large stainless steel skillet or wok over medium-high heat until it begins to shimmer.
Add the beef strips to the hot pan in a single layer and sear for 2-3 minutes until deeply browned and caramelized, then remove the beef and set aside.
Add the broccoli florets to the same pan with a splash of water, immediately covering with a lid for 2 minutes to steam-tenderize while maintaining a bright green color.
Remove the lid, return the beef to the pan, and pour the prepared sesame glaze over the mixture.
Toss everything together for 1 minute until the sauce thickens and coats the ingredients in a glossy finish.
Plate the stir-fry and garnish with sesame seeds before serving.