The Art of Preparing Monkfish Liver

Monkfish liver.

As a chef, and working through fine-dining restaurants for the last decade, I had never come across such a product as monk liver. I thought to myself “What is this strange beast?” So, I set out on a quest in Samuels wealth of knowledge to conquer this unfamiliar product.

One of the first questions I asked before even diving into this product was why monk liver – why not other livers from fatty fish like salmon or tuna? I sat down and spoke with our resident chef, Davis Denick, the Vice President and marine biologist, Joe Lasprogata, and one of our Japanese product specialists, Shinobu Habauchi and discovered the following facts.

What it really comes down to is fat content. Monkfish liver clocks in at 40% fat, while other fish like snapper and tuna are 2% and 3% respectively. Foie gras, or goose liver, has a fat content of 46% – but that extra amount makes all the difference in the way you process it. You can’t cook a lean piece of protein the same way you’d cook a fatty one.

Besides Monkfish liver, there are other fish livers used in culinary applications, mostly hailing from Asian origins. These fish include snapper, filefish, leatherfish, great sculpin, and green ling. These are used mostly as thickening and flavoring agents in soups and sauces, so they really have a lot of deep flavor in them after they are processed. Think along the lines of miso meets fish sauce and used like uni.

When inspecting your monkfish liver, you’ll want to ask your fish monger when they were brought in because being an organ, they have a limited shelf life. Maybe, five days max. You also need to be aware of the amount of black spots and grey discoloration that may occur in the liver. This can be cut out and won’t affect the final taste of the product, but you need to be wary of your yield.

Now, I’ve worked with liver before, usually in mousse or torchon – and you’re probably familiar with this as well. It would make sense that you treat this the same way, if you are doing the same execution; but there are some differences that you need to understand before approaching Monkfish Liver:

  1. Rinse and pat your liver dry. A lot of times organs will purge liquid and it is very metallic in flavor – not what you want in your liver.
  2. Marinating is the key. Go heavy on your aromatics. You want to impart as much flavor as possible before you cook it. Marinade 4-6 hours.
  3. Butcher as you would fresh foie gras. Remove the veins with your knife and a pair of pliers.
  4. Unlike foie gras, Monkfish liver is very delicate – so handle with care.
  5. It is most ideal during the cold winter months because when the water is warm, the liver is very prone to parasites during this time; and although you won’t die or get sick from eating cooked parasites, it’s not something you want to mess around with.
  6. If done properly, the finished product will have a flavor profile similar to a west coast oyster. It’s going to be creamy, smooth, and fatty with a slight metallic finish – but not like your sucking on a bunch of coins.

This application uses thyme, rosemary, lemons, lime, orange, garlic and onion powder, cardamom, Dijon mustard, white balsamic vinegar, Santa Ines olive oil, salt and pepper; but you can use your favorite ingredients or create your own flavor profile.

If you’re doing a torchon, you’ll want to remove as much of the marinade from the liver as possible. Lay out your plastic wrap and place the liver on it. Fold the plastic over and start to form a cylinder; pinch the ends and roll until it becomes tight. If you get air bubbles or pockets in your roll, use a fork and poke a small hole in it to remove the air. Follow this up with another tight roll so no water leaks in. Poach for 3 hours at 62° Celsius in a sous vide water bath. Once the cooking is complete, move to the fridge and allow to set 8 hours, or overnight. Keep in mind that this will oxidize and discolor, so you may want to remove the plastic from the section you are going to use only. This is great to sear afterwards, because unlike foie gras, you have a bit more of a yield since there is less fat.

For a mousse application, you’ll want to get a good, quick sear on the liver. Remove the large garnishes in your marinade, and pat the liver dry. Next, cut the liver into 1-2 ounce chunks, or at least make them all the same size. In a scorching hot pan with a little bit of oil, sear the liver pieces. You want this to be between rare and medium rare so the carry over heat doesn’t over cook your livers, resulting in a grainy, bitter taste. Once you have a sear on these, remove them from the pan, but do not scrape the pan! Reduce your heat to medium, add a knob or two of butter and then sweat shallots and garlic in the pan. Once they begin to caramelize, deglaze with aged sherry or cognac. Allow this mixture to reduce until it is almost syrup. Then, add heavy cream and reduce by half. Add this liquid and the livers in a blender or food processor blend with a pinch of xantham gum (use a small amount and then add accordingly, this is very strong) or another thickening agent, until it becomes smooth.  You don’t want to over process this at all, it can become grainy and/or rubbery. Once smooth, taste and adjust seasoning. You can finish this with fresh lemon juice for acid, tamari or Worcestershire for salt; add some depth with aged balsamic or sherry, and cracked black pepper or hot sauce for extra seasoning.