Slice off the ends of the stems of the mushrooms and wash. Thinly slice the onion, carrot and shiitake mushrooms. Remove the bones from the cod pieces.
Lay the cod pieces on sheets of foil. You can use frozen fish as is, without thawing. We are making 2 sets, so lay one piece of fish on each sheet of foil.
Lightly season the fish with salt and pepper. Put the onion, carrots, shiitake mushrooms (or shimeji), and enoki mushrooms on top.
Lay a piece of butter in the middle. Combine the ● ingredients (dissolve the miso) and drizzle on top.
Cover with another piece of foil. Roll the foil 2-3 times to close the edges tightly. Make sure there are no holes!
Put the foil packages in a frying pan, cover with a lid and steam-cook for 10-15 minutes over low heat. Serve with ponzu (or soy sauce) drizzled on top.
※ Shorten the cooking time if you aren't putting in enoki mushrooms because there will be less moisture and it will burn easily.
Story Behind this Recipe
This is a standard recipe at our house. There's also "Steamed Cod in a Microwave" Recipe ID: 325208, which is even easier.
You can use fresh cod as is, but if using salted cod, soak in water to remove the salt before use. If the foil packets look like they're about to burst while cooking, turn of the heat and let them sit covered for a few minutes before serving. I sliced the carrots in the photo into rounds, then cut out heart shapes with a cutter. I recommend using white wine instead of sake.