1. Season the chicken lightly w/salt and pepper. In a lg. skillet, heat the oil over hi heat. Stir-fry the chicken, stirring constantly, until golden and nearly cooked through, about 4 min.
2. Stir in the garlic, ginger and lemongrass and cook, stirring, for 30 seconds.
3. Add about half of the green onions, the broth and fish sauce. reduce the heat to med and simmer until the chicken is cooked through and the sauce is slightly reduced, 2-3 min.
4. Stir in the remaining green onions and the cilantro.