Slice the flank steak against the grain into thin, bite-sized strips for maximum tenderness.
In a small bowl, whisk together the coconut aminos, minced ginger, and minced garlic to create the base sauce.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat until it begins to shimmer.
Add the beef strips to the skillet in a single layer, seasoning with sea salt and black pepper, and sear until browned on all sides.
Remove the beef from the pan and set aside, then add the broccoli, bell peppers, and snap peas with a tablespoon of water.
Cover the pan and steam the vegetables for 2-3 minutes until they are bright green and tender-crisp.
Return the beef to the pan, pour the sesame-ginger sauce over the mixture, and toss for 1 minute until everything is glossy and well-coated.
Transfer to a plate and garnish with sesame seeds for a final crunch.