1. Place fillets in a large baking dish and sprinkle thyme, parsley, lemon and orange zests onto flesh side of trout. Gently press into fish, cover, and refrigerate for 4 hours or preferably overnight.
2. Bring fish to room temperature before cooking and season with salt and pepper.
3. Place 2 large frying pans on the stove. Add 1 tablespoon of oil to each pan and place fillets skin-side down in frying pan.
4. Turn heat on pan to medium high and cook until skin begins to turn golden brown and crispy, about 5-6 minutes, adjusting heat as necessary. Flip and cook a further 2 minutes on the other side, until fish is just cooked through and pink in the center. Remove to a platter and let sit, lightly tented with foil to keep warm.
5. While fish is cooking, place a large shallow saucepan over high heat.
6. When pan is hot, add remaining oil and then add the bok choy, cut side down.
7. Cook for 5 minutes, or until caramelized, then add the shallot, ginger, garlic and thyme. Stir and cook 1 minute to release flavors.
8. Add the stock and soy sauce and cover. Bring the liquid to a boil, reduce the heat and simmer the bok choy on low for 5-7 minutes, until tender.
9. Remove bok choy from pan and increase the heat to medium-high, reduce the liquid until slightly thickened, about 3 minutes. Stir in the butter.
10. To serve, place bok choy on platter and top with trout, drizzle with sauce and serve.