Mix the beef with the marinade ingredients in a bowl and let it sit for 10 minutes.

Cut the bok choy into 3cm pieces, separating the stems and leaves. Mince the garlic.

Combine the sauce ingredients in a separate bowl and mix well.

Heat half of the sesame oil in a pan, add the beaten eggs, and stir-fry over medium heat briefly. Remove from the pan.

Add the remaining sesame oil and garlic to the pan. Cook over low heat until fragrant, then add the bok choy stems and stir-fry over medium heat until softened. Remove from the pan.

Add the marinated beef to the pan and stir-fry over medium heat until the color changes. Add the bok choy stems, leaves, and cooked eggs, and stir-fry together.