Saikyo-Yaki: Miso Marinated Spanish Mackerel
There are many days where I'm cooking for 8-10 hours straight knowing fully well that I need to also cook dinner when I get home. My dear husband never pressures me to cook for us but that's how I originally got into cooking so I really cherish sitting down at the table together. For the stressful days, miso marinated mackerel (さわらの西京焼) is my secret tool. Almost all of the work is done ahead of time and it can sit in the fridge for 1-3 days. On the days I already have mackerel marinating in the fridge, there's a huge sense of relief. Because I know that when I get home I can microwave frozen rice (I am definitely not above microwaving), sauté some Chinese vegetables and pop this baby in the oven and have a balanced delicious dinner. It takes some planning ahead but it makes life extremely easy when it's time to cook.
Most people in the US have probably encountered a similar dish in sushi restaurants as an appetizer using black cod (aka sablefish) made famous by Chef Nobu Matsuhisa. But before this dish became a sushi joint staple, Japanese families have been preparing Spanish mackerel the same way. And it helps that Spanish mackerel is significantly cheaper than black cod. It has a similar buttery flavor and texture so it stands up to heat extremely well. Speaking of buttery fish, salmon also works really well in this dish, especially the fatty belly which I always try to take home from work.
You can start off with filleted mackerel or the whole fish (I used a 2lb whole fish). If you need help choosing fish at the market, I wrote a quick guide a few weeks back. Unlike branzino in that post, mackerel lacks scales so it's very easy to clean the fish yourself when you get home. But any good fishmonger should be able to clean and fillet it for you.
You can also ask your fishmonger to take out the pin bones (which there are quite a few in mackerels) but you definitely want to do a quick check before you start marinating. If there are pin bones still left, you can use a tweezer or a needle nose plier to get them out. I have a Wusthof fish plier from culinary school but there is no need to spend money here, just get some from the hardware store and use it exclusively for fish. Unlike salmon, cod, or bass (pretty much any other fish), mackerel pin bones are quite tough to get out. If you'd rather keep the flesh completely in tact and don't mind pulling the bones out as you eat, that's also an option. To check for pin bones, run your finger down the bloodline (the center line where the pliers are pointing). Most of them will be closer to the head of the fish and will trail off as you move towards the tail.
Once you have clean fillets, cut it into 3-4 pieces on a bias (or not, the bias just looks pretty).
Whisk up white miso (the lower the sodium the better for this), mirin and sake until the miso is evenly distributed. I usually do this in an airtight glassware so I can just plop the fish right in, stick it in the fridge and forget about it.
Add the fish in and make sure that each layer of fish is coated with the miso marinade. Close the lid and stick it in the back of your fridge for 1-3 days.
On the day that you're actually eating the mackerel, preheat the oven to 450°F, wipe off the marinade with a paper towel and lay the fish on a sheet tray lined with aluminum foil (don't worry the fish is plenty cured at this point so you do not need any more seasoning). Depending on the thickness of the fish, it should take anywhere from 10-20 minutes for the flesh to become flakey. It's easy to tell when it's cooked through because the translucent flesh turns opaque. Some color and bubbling of the skin is a good thing so don't fret. Definitely pair this dish with some unseasoned Japanese white rice to balance the bold flavors and enjoy!