Rinse the cod fillets under cold water and pat dry.
Clean the bok choy and remove from stem. Reserve in a damp towel in the refrigerator until ready to cook.
In a medium bowl, add the wine, scallions, sugar, ginger, 1 tablespoon rice wine vinegar, soy sauce, sesame oil, orange zest and chili pepper, if using. Cover and place in the refrigerator to macerate.
In a small bowl, add the radishes and orange segments. Add 2 tablespoons of rice wine vinegar, 3 tablespoons of canola oil and season with salt and pepper. Reserve this with other ingredients until ready to use.
Turn on your steamer to high and let the steam start to build for about 5-8 minutes. I use a bamboo steaming basket with 2 levels placed over a pot of rapidly boiling water. The lower section is for the fish and the upper is for the bok choy. If you don’t have this option, you can simply blanch the bok choy in lightly salted boiling water for 2-3 minutes.
Season the fish with salt and pepper and add to the steamer once the water is rapidly boiling and the steam has accumulated.
Quickly close the steamer and reduce the flame (or your steam setting) to medium. Let the cod cook gently for 4-6 minutes. The fish should be opaque and almost cooked all the way through. It will carry on cooking even when removed from the steamer, so be careful as to not overcook the fish.