Cut the lamb into thin strips. Combine with the marinade ingredients. Marinate the lamb for 25 minutes.
While the lamb is marinating, prepare the sauce and other ingredients.
In a small bowl, combine the sauce ingredients. Set aside.
Heat the wok over medium-high to high heat. Add 2 tablespoons oil. When the oil is hot, add the garlic. Stir-fry until aromatic (about 30 seconds).
Add the lamb. Stir-fry very briefly, until the lamb changes color (1 to 2 minutes).
Add the sauce. Bring to a boil.
Stir in the scallions. Taste and season with salt and pepper if desired.
Stir-fry for 1 more minute, or until the sauce is absorbed.
Remove from the heat, stir in the sesame oil, and serve.
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.