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 tamari, toasted sesame oil, honey, and red pepper flakes to create the stir-fry sauce.
Heat the avocado oil in a large skillet or wok over high heat until shimmering.
Add the beef strips in a single layer and sear for 2 minutes until browned, then remove from the pan and set aside.
Add the broccoli florets and a splash of water to the same pan, covering with a lid for 2 minutes to steam until vibrant green.
Remove the lid, add the minced garlic and grated ginger, and sauté for 30 seconds until fragrant.
Return the beef to the pan, pour the sauce over the mixture, and toss everything together for 1 minute until the sauce thickens and coats the ingredients.
Garnish with sesame seeds before serving hot.