Prep all your chicken and vegetables before you begin, and set them aside.
Heat a wok over medium heat and add enough oil to coat the pan.
Add the chicken and salt to taste. Cook until the chicken is browned and reaches 175 degrees when checked with an instant-read thermometer. Stir the chicken often as it cooks.
Remove the chicken from the wok and set it aside. Add the carrots and celery at the same time. Drizzle with oil if necessary and season with salt to taste. Cook until the carrots and celery are tender. Set aside
Add the core/stem of the Napa cabbage. Drizzle with oil if necessary and season with salt to taste. Cook until the cabbage starts to become translucent, then add the rest of the Napa. Cook until tender. Set aside
Now, cook the snow peas. Drizzle with oil if necessary and season with salt to taste. When the peas are browned and tender, set them aside.
Add the onions and cook until softened. Keep the onions in the wok as you prepare the sauce.