Steaming fish in its own marinade is a brilliant and heathy way to inject some serious flavour.
Based on 4 servings, adjust as needed.
Preheat your oven to 200°C/180°C Fan.
Cook sweet potato in a large pot of salted boiling water over medium-high heat until tender, about 12 minutes. Drain, mash and combine with lime zest, half the juice, maple syrup, most of the coriander leaves and oil. Season to taste.
Create fish marinade by combining the fish sauce, tamari, garlic, remaining maple syrup and remaining lime juice in a small bowl.
Cut four large foil squares. Divide red onion and pak choi evenly between the four squares, then top each square with a piece of fish and finally pour the marinade evenly over the fish. Fold the foil over and seal the edges to enclose the fish, veggies and marinade completely inside the parcel.
Place into your oven and bake until the fish is just cooked through and the vegetables tender, 17-20 minutes.
Once the fish is ready, remove from the oven, open parcel carefully and sprinkle with remaining coriander. Serve together with your sweet potato mash.