Thinly slice the flank steak against the grain into bite-sized strips to ensure maximum tenderness.
In a small bowl, whisk together the tamari, toasted sesame oil, raw honey, grated fresh ginger, minced garlic, red pepper flakes, and water to create the stir-fry sauce.
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 without moving them to develop a deep brown crust, then flip and cook for another minute until just browned.
Remove the beef from the pan and set aside on a plate.
Add the broccoli florets and a splash of water to the same pan; cover with a lid for 2 minutes to steam until vibrant green and tender-crisp.
Return the beef and any accumulated juices to the pan, then pour the sauce over the mixture.
Toss everything together for 1-2 minutes until the sauce thickens and coats the beef and broccoli beautifully.
Garnish with sesame seeds and serve immediately while hot.