Peel zucchini and cut into approximately 1-1/2" lengths. Make the lengths of zucchini into cups by scooping out the seeds in the center, but leaving small amount to form the bottom of the cup. You may need more or less zucchini than the amount given, depending on their size. In a bowl, mix the ground pork or chicken with fish sauce, eggs, ground white peppers, and cilantro. Fill the zucchini cups with the mixture, and overfill slightly to make a small mound. Cook the filled zucchini cups by steaming for about 1/2 hour. Bring the chicken or pork stock to a boil, and season to taste. Place the precooked zucchini cups into a serving tureen, pour the boiling stock over them, and serve. Translated by Padej Gajajiva from "Rattanakosin Dishes, 1982", Momluang Terb Xoomsai.