Boil the shank for 8-10 minutes. Peel off the skin and marinate for 2 hours in the marinade.
For marinade: mix chicken broth, anise, milk, ginger, fish sauce, tangerine zest, garlic, ginger, chopped onion, soy sauce, red pepper, sugar salt).
Bake the shank until tender, pour the marinade sauce over when serving, garnish with parsley and stewed pak choi when serving.