Oil-Poached Fish: Halibut and Avocado Salad

Oil-Poached Fish: Halibut and Avocado Salad

Okay, okay, okay. I get it! Some people are afraid to cook fish at home. But I can’t really figure out why. I’ve tried to convince people that cooking fish is as easy as it is delicious. In the past, I’ve shared a few simple methods for grilling and pan-frying fish that I believe are easy to master. However, in case you still fear gill on the grill (or perch in the pan) let me introduce you to oil-poached fish. It’s a very simple technique that results in the most tender, moist and luxurious seafood imaginable. Oil-poached fish is a revelation to cooks and non-cooks alike. It takes very little effort because it requires very low heat.

Cooking fish becomes quite simple once you learn that great results can be had at the gentlest temperatures. If you’re grilling, grill over a mellow flame, not a blazing fire. If you’re steaming or poaching, do it at the barest of simmers. Believe it or not, you can cook salmon to flaky perfection in a 120°F oven. In fact, cooking salmon low and slow reveals textures you never thought possible. Which isn’t to say you can’t get great tasting fish in a hot pan. It just takes a little more attention from the cook.

Not so with oil-poached fish. It takes almost no attention. This foolproof method delivers the silkiest, most luxurious piece of fish you’ve ever had.

Oil-Poached Fish

Oil-Poached Fish: Choosing the Fish and the Oil

The best fish for oil poaching are rich in flavor and firm in texture. As I said shrimp, salmon, tuna and halibut are all perfect choices. The only trick is to choose steaks or fillets that are 3/4 to 1 inch thick.

The best oil for poaching is extra-virgin olive oil in my opinion. It has a rich, floral taste that requires very few amendments for the best flavor. However, this is not the time to reach for your most precious drizzling oil as poaching requires quite a bit of the stuff.

Oil-Poached Fish: Seasoning

Fish must be seasoned before cooking. The easiest way is to simply remove the fish from the refrigerator and shake a little salt and maybe a touch of pepper on both sides then let it sit at room temperature for at least 20 minutes. I use this method quite often because it takes no planning. However, with just a little forethought, I prefer to brine fish – much like you do with pork, turkey or chicken. It’s a great way to get fish seasoned all the way through. It also helps keep the fish from drying out when cooked over high or direct heat. However, it does something else. It firms the flesh, making it cook up a bit meatier and less likely to fall apart. I use a 5% brine solution. Which works out to be about 1/4 cup sea salt to 6 generous cups of icy water. Average size fish fillets will be seasoned and ready to cook in about 1 hour. Rinse and dry them thoroughly before cooking.

Oil-Poached Fish: The Pan

Choose a straight-sided sauté pan or saucepan that will hold the fish in a single layer. It’s fine to crowd the pan as long as the fish doesn’t overlap.

Oil-Poached Fish: Heat

Add just enough oil to submerge the fish completely. Then heat the oil over low to medium-low heat to 120°F. Use a candy or instant-read thermometer to check. Add the fish AFTER the oil has heated and continue to monitor the temperature during cooking.

Oil-Poached Fish: Timing

The most remarkable thing about this technique is that the timing is truly foolproof. Twenty-five minutes at a consistent 120°F will result in perfectly cooked seafood every time. It’s important to start with room temperature fish. Fresh-from-the-fridge fish will throw off the cooking time. Let it sit for about an hour before poaching. No, you won’t get food poisoning and die (provided of course you keep at least a semi-clean kitchen).

Oil-Poached Fish: Leftover Oil

Oil-poaching can take up to 6 cups of oil. Don’t let that scare you off. You can use the oil 3 or 4 times to poach more seafood. Let it cool to room temperature and then strain it through a fine sieve lined with paper towels. Stop straining before you reach the bottom. The liquid released from the seafood will have settled there. Discard this last bit. Store covered in the refrigerator for up to three weeks.


raw halibut frilletAvocado

Oil-Poached Fish: Halibut and Avocado Salad

Oil-Poached Halibut and Avocado Salad 

Print This Recipe Total time Yield 4Source Adapted from Nan McEvoyPublished
Oil-Poached Halibut and Avocado Salad


  • ¼ cup kosher salt (plus more for seasoning)
  • 2 cup water
  • 4 cup ice cubes
  • 1 pound halibut fillets
  • extra-virgin olive oil (as needed for poaching)
  • 1 tablespoon whole mustard seeds
  • 1 tablespoon whole black peppercorns
  • ½ cup mayonnaise
  • 4 anchovy fillets (minced)
  • 2 tablespoon capers (drained and chopped)
  • 1 clove garlic (peeled and minced)
  • 2 tablespoon freshly squeezed lemon juice (divided)
  • 1 celery rib (thinly sliced crosswise)
  • ¼ cup finely diced red onion
  • ¼ cup pitted and chopped oil-cured black olives
  • 2 avocados (halved and pitted
  • 1 cup sprouts or micro greens (for garnish)


Combine kosher salt and water in a large mixing bowl and stir to dissolve the salt; add ice. Place the fillets in the brine and set aside for 1 hour. Remove the fish from the brine, rinse and dry it thoroughly with paper towels. Lay fish on parchment-lined baking sheet and refrigerate unwrapped about 1 hour. Bring the fish to room temperature before continuing.

In a medium, straight-sided saucepan set over low heat, combine enough olive oil to cover the fish with the mustard seeds and peppercorns. Heat oil to 120 degrees F. Place halibut in oil and poach for 25 minutes. Monitor the temperature to assure a consistent 125 degrees F. throughout the cooking. Once cooked remove the fish from the oil. Cool and drain the fish on a rack set over a tray. Cool, strain and reserve the oil for poaching more seafood.

Meanwhile, in a large bowl, blend the mayonnaise, minced anchovies, capers, garlic and 1 tablespoon fresh lemon juice. Stir in celery, onion and olives. Using a fork, break halibut into bite-sized pieces, then gently fold into the mayonnaise mixture. Season with salt.

Set an avocado half on each of 4 plates, skin side down. Drizzle or brush the avocado flesh with remaining 1 tablespoon of fresh lemon juice. Spoon 1 cup of the halibut salad into the center of each avocado half. Top the with sprouts or micro-greens and serve.