Slice the flank steak into thin strips against the grain. Pat dry and season with the salt.

Mince the garlic and grate the ginger. Whisk the coconut aminos, beef broth, and sesame oil in a small bowl.

Heat 1 tablespoon of avocado oil in a large skillet or wok over high heat. Sear half the beef in a single layer, 1 to 2 minutes per side, until browned. Move to a plate and repeat with the remaining beef.

Add the remaining oil and the broccoli to the pan with 2 tablespoons of water. Cover and cook 2 to 3 minutes, until bright green and crisp-tender.

Add the garlic and ginger and stir for 30 seconds, until fragrant. Pour in the sauce and bring to a simmer.

Sprinkle the xanthan gum evenly over the sauce while stirring. Simmer 1 minute until glossy and slightly thickened.

Return the beef and any juices to the pan and toss to coat. Top with sliced green onion and sesame seeds and serve.