Heat a wok or a large skillet over high heat. Add the peanut oil and heat until very hot. Add the chicken and stir-fry until lightly browned, about 5 to 7 minutes Add the garlic and ginger and stir-fry until fragrant, about 30 seconds. Add the celery, Napa cabbage and carrots and stir-fry until the vegetables are crisp-tender, about 2 minutes. Pour the chicken broth mixture into the wok and bring to a boil. Cook until sauce thickens and the chicken is cooked through, about 1 to 2 minutes. The chicken is done when it feels firm to the touch and a meat thermometer inserted in the center reaches 170°F.