Slice the flank steak against the grain into very thin, bite-sized strips.
In a small bowl, whisk together the tamari, honey, grated fresh ginger, and minced garlic to create the stir-fry sauce.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat until shimmering.
Add the beef strips to the hot skillet in a single layer, seasoning with sea salt and black pepper.
Sear the beef for 3-4 minutes until nicely browned and just cooked through, then remove the beef from the pan and set aside.
Add the broccoli florets to the same skillet with a splash of water, cover with a lid, and steam for 2 minutes until tender-crisp and bright green.
Return the beef to the skillet and pour the prepared sauce over the mixture.
Toss everything together for 1-2 minutes until the sauce thickens and coats the beef and broccoli in a glossy glaze.
Garnish with sesame seeds and serve immediately.