Stir-fry the chicken
Season the chicken with salt and pepper. In a wok or large frying pan over high heat, warm the oil. Add the chicken and stir-fry until golden on the outside and opaque throughout, 2–3 minutes. Transfer to a plate. Add the green onions and stir-fry until fragrant, 1–2 minutes. Add the ginger, lemongrass, and garlic and stir-fry for 30 seconds. Add the asparagus and stir-fry just until tender-crisp, 2–3 minutes.