Slice the flank steak against the grain into very thin strips and season evenly with sea salt and black pepper.
In a small bowl, whisk together the tamari, toasted sesame oil, raw honey, minced fresh ginger, and minced garlic to create the stir-fry sauce.
Heat the avocado oil in a large wok or cast-iron skillet over high heat until it begins to shimmer.
Add the beef strips in a single layer and sear for 2 minutes until browned and caramelized, then remove the beef from the pan and set aside.
In the same pan, add the broccoli florets, sliced bell peppers, and snap peas, tossing frequently for 3 to 4 minutes until they are tender-crisp.
Return the beef to the pan and pour the prepared sauce over the mixture, tossing everything together for 1 minute until the sauce thickens and coats the ingredients.
Serve the hot stir-fry over the warm cooked brown rice and garnish with a sprinkle of sesame seeds.