Preheat the oven to 400°F. Line a baking pan with aluminum foil and set aside. Finely chop 1 scallion and slice the other 2 into 1 inch bias. In a large bowl, whisk together the chopped scallions, garlic, ginger, egg, soy sauce, oil, five spice, salt and pepper. Add in the chicken, pork and bread crumbs and mix well. Form the mixture into ¾ inch meatballs and place on the prepared baking pan. Place in the oven and bake for about 8 to 10 min, or until lightly browned. Remove and set aside.
In the meantime, in a Dutch oven, over high heat, bring the stock to a boil. Lower heat to low, add in the garlic powder, ground ginger, star anise and mushrooms and simmer gently for 10 to 15 min, or until the mushrooms are hydrated and tender. Remove the star anise. Add in the carrots, bok choy and meatballs and simmer until tender, about 10 minute.
Cook the rice sticks according to package directions. Drain and evenly divide the noodles amoung 6 large bowls. Thinly slice the mushrooms then arrange the carrots, bok choy, mushrooms and meatballs on top of the noodles. Ladle in the broth, garnish with remaining scallions and serve.