There is a Japanese technique which may be new to you in this recipe. Taking this special step is necessary in order to produce clean and delicious flavor in the prepared dish.
The technique is called Shimofuri, which literally means ‘frost-covering’. In this technique we first blanch scaled and cleaned fish in hot water in a pot until the surface turns white resembling frost. Then carefully cool and rinse the fish in a bowl of cold water with tap water running into it. By doing this fish sheds off-flavors and becomes clean allowing the simmering broth in the next process to remain clean, clear and delicious.
After Shimofuri we place the fish in a shallow and large pot in which fish fillets can be placed without overlapping. We simmer the fish in a mixture of dashi, kelp stock or water, sake and mirin. This mixture barely covers the fish. The proportion of dashi/kelp stock, sake and mirin is 3:1:1. Add few slices of peeled ginger to the pot to enhance the flavor of the fish.
After cooking the fish about 10 minutes, covered with a drop lid (if you do not own a Japanese wooden drop lid, use a disc of parchment paper cut to just fit into the pot on top of the simmering ingredients), about 10 minutes, add the shoyu in the same quantity as the mirin. Cook until the cooking liquid is reduced by half. The cooking time varies depending on the size of the fish in the pot usually about 10 minutes. Serve the fish with a portion of the cooking liquid.
If karei (flounder) is not available, use salmon steak (with bones). If you can get wild-caught pompano, try it with this meaty, delicious fish. Nizakana is a wonderful fish dish enjoyed by everyone during the colder seasons.