Seafood Recipes

Herb and oil poached fish

September 7, 2010

Some things automatically go against the grain. Dumping two bottles of half decent olive oil in to a pan, and then loading it up with fish and herbs for instance. However, 20 minutes later and it all becomes understandable. Tender, flaky moist fish with such a delicate flavor and texture. If you get it right, the fish just quivers as you carry the plate to the table. This to me is the very exciting sign of a perfectly cooked piece of fish. It can seem like you don’t even need to touch it with a fork, merely just get it close, to see it flake in to pieces. Each bite yields perfectly cooked fish throughout, with subtle flavors pulled from the oil and herbs.

I first started cooking fish this way a couple of years ago and haven’t stopped since – especially in the summer since this yields light, but rich fish. Originally it seems like an extravagant preparation, requiring a lot of oil that will no doubt get junked after cooking. Screw it up, and you waste a good job lot of olive oil, and some lovely pieces of fish. Get it right and you would be hard pushed to find such an intricately flavored piece of fish. Thankfully, it really isn’t hard to do – a careful eye and an instant read thermometer (or a fancy candy thermometer) and you are set.

Whilst some cooking methods can easily remove moisture from food (roasting for one), cooking fish in oil doesn’t. If you keep the temperature low enough the oil almost seems to add to the richness of some fish (cod in particular), and provides a delicate fruitiness to the taste of the fish flesh.

Oil poached fish is great paired with simple summer vegetables. A little beet salad, some leafy greens and you are away. Some grilled zucchini and some freshly made hummus is also a favorite pairing of mine at the moment (more on those bad-boys later..) If you find the fish too rich, top with some simple pickled carrots or onions (or anything). Why not flake the fish up, mix with some cooked beans (or chickpeas) and a little arugula? Dress with sherry vinegar and some oil from the poaching – not forgetting salt and pepper and you have a great fish salad.

Did I mention that fish prepared this way is great cold too? I oil poached some local albacore tuna like this last week (which is incidentally the photo above – a quick snap whilst cooking) to have as an office lunch, along with a lovely French lentil salad.

The biggest key to success in oil poaching fish is controlling the temperature. You want the oil to be at a temperature of about 120F. Anything above 135F and you start to get towards overcooking and drying out the fish. Gentle and slow are the rules here. Now, I have a gas range and even on my simmer burner it is hard to keep a temp that low. The best thing to do is to be watchful, and pull the pan from the heat for a few minutes, and then put it back on as the temp goes down to, say 115F. A piece of fish about 1.5 inches thick is going to take 15 or so minutes to cook at this rate.

What fish can you oil poach? Quite a lot really. I like to poach fish fillets that have good thickness to them. Here in the Pacific Northwest, local albacore is fantastic like this. Salmon is delicious this way too. This turns something as neutral as true cod into a complexly flavored perfectly cooked piece of fish. Black Cod (Sablefish) is great this way too. You could even then take the Black Cod and crisp up it’s skin in a separate skillet once poached (careful not to overcook the fish though).

Top tips for oil poaching fish:

  • Pick fresh fish, with a good thickness to the fillet for the most rewarding oil poached fish. 1.5″ to 2″ fillet thickness is a good bet.
  • Use a good quality oil, but not something expensive and amazing since you will be using a lot of it.
  • It is easiest to poach fish with skin on. This helps them keep together.
  • If you don’t have enough oil in your pan, and the top of your fish is sticking out.. Don’t fret, every so often spoon some of the warm oil over. Half way through cooking, gently roll the fish over so that top is now bottom.
  • Use an instant read thermometer or candy thermometer to keep a close watch on oil temperature. 120F is perfect.
  • The fastest way to cool the oil down if it gets too hot is to remove the pan from the heat.
  • The easiest way to control the heat is also to move the pan on and off the heat, being careful as you do.
  • The fish can be kept off the heat, in the warm oil for a few minutes whilst you finish the rest of a dish you are making.
  • Flavor the oil with fresh herbs if you wish – details below!
  • If you are flavoring the oil with herbs, heat them in this oil until about 160F. Let this sit for 20minutes to infuse, then cook the fish in it.

Oil poached fish recipe:

(serves 2)

8-10oz fresh fish fillet (see fish species advice above)

4-6 cups of decent enough olive oil

sea salt to taste (a good pinch)

4 bulbs of garlic

herbs of choice – rosemary, thyme, savory, oregano are all good choices

1) if you are using herbs – put the oil in a pan, big enough to hold the oil and the fish. The smaller the pan, the less oil you have to use. Put the herbs in the oil, along with a pinch of salt.

2) Heat the oil up till pretty hot – say 180F. Remove from the heat, and let cool back down to 120F or lower – say 30minutes. This steeps the herbs in oil, adding flavor to it.

3) Pat the fish fillet dry. Cut in to two pieces.

4) Heat the oil gently until it reaches 120F. Check with an instant read thermometer or candy thermometer.

5) Gently add the fish to the oil.

6) Keep the heat of the pan around 120F – move the pan on and off the heat as required to maintain a consistent temperature.

7) Depending on the thickness of the fish, they might take about 15 to 20 minutes to cook through.

8) Test the fish by taking a piece out and trying to flake it with a fork. It should flake easily, and be just opaque all the way through.

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  • Paula September 7, 2010 at 8:15 am

    sounds great!

  • Elizabeth September 7, 2010 at 5:43 pm

    Beautiful recipe. I have never oil poached anything but I have an amazing sockeye salmon sitting in my fridge just waiting for this recipe. Delicious!

  • Serene September 7, 2010 at 8:34 pm

    Oh, my, I think I would just be too afraid (read: too cheap!) to do this with so much olive oil, but wow, it looks wonderful!

  • Janet September 8, 2010 at 1:38 pm

    Oooh, yum! I have done this with lemon slices and some herbs. But, big difference. I poach mine in the oven. Same results but way easier than stovetop.

  • Yue Edwards September 8, 2010 at 7:10 pm

    wow, looks great!!! so it’s like low heat deep fry. I wonder how much oil is the fish absorbed. In Chinese cuisine, we have something similar to this, but use less oil and we add water seconds after the fish is poached in oil and boil it for a short while. Right after transfer the fish to a deep dish, we pour in the dish more hot oil and it makes the sizzling sound~

  • Heather September 8, 2010 at 8:30 pm

    GORGEOUS. You can can fish in oil this way, too. You can always save the oil to use for future fish poaching, or for saucing other fish dishes, couldn’t you? If the oil is refrigerated it wouldn’t go rancid.

  • Michelle September 9, 2010 at 2:40 pm

    I really appreciate how thorough your posts are. You offer SO much quality information for cooks. It’s a lot of hard work on your part, but it is that – along with your exceptional photography (of course!) and inspiring recipes – that makes you stand out amongst all of the food bloggers out there. This site is so very special. Thank you Matt!

  • MyPigsGood September 9, 2010 at 4:48 pm

    I have wanted to try this since seeing Kevin do it on Top Chef, but have always balked at the idea of using a $10 bottle of oil for one meal. Looks amazing. Perhaps I will just have to bite the bullet and give it a try.


  • matt September 9, 2010 at 6:19 pm

    Paula – its my new fav. way of cooking fish!
    Elizabeth – Have a go, let me know how it turns out!
    Janet – good idea to use the oven. Mine doesn’t get a low enough temp however.
    Yue – It isn’t really a fry at all, the temp is so low – just a rich poach.
    Heather – Yeah, I totally agree you could strain the oil then use for future poachings. I should do that next time.
    Michelle – thanks so much, you are too kind!
    MyPigs – As Heather suggests above, you could strain the oil and keep for future poachings – once you try it, you will be hooked!

  • Kendra September 13, 2010 at 7:33 pm

    I love the suggestions to “save the oil for future poachings.” That may be just the encouragement I need to give this decadence a try…

  • Kevin September 14, 2010 at 8:45 pm

    That looks fantastic! And “decent enough olive oil”. I think we all have some of that lying around. Usually as a gift from the in laws when they find out we like to cook 🙂

    Found you through Twitter by the way, when you were envying one heck of a meat slicer.

  • Scott at Real Epicurean September 17, 2010 at 9:57 am

    It does look a really original way to cook fish…Worth a try if I ever have enough oil lying around unused.

  • graZOR October 18, 2010 at 4:15 pm

    Matt this is laaahvully!

  • Geraldine Moloney March 10, 2011 at 11:32 am

    Matt, Thanks for sharing, it sounds unusual, and certainly tasty. I really look forward to trying it. I guess, cod, or, monkfish might be good options?

    • mattwright March 11, 2011 at 4:50 am

      Cod would be a good option. Monkfish is not a good option as it is far from sustainable, and most are harvested by bottom trawling a fishing technique which greatly damages the ocean habitats.

  • dionysos March 11, 2011 at 11:18 pm

    I don’t agree with the oil poaching temperature of 120 ℉ . In fish cooking slow and gentle heating can develop an custard like unpleasant and mushy texture if heated to
    120 ℉ . Caused by protein digesting enzymes in the muscle cells of active fish and shellfish that convert muscle mass into energy . Some of these enzymes become increasingly active as the temperature rises during cooking until they are inactivated at 130 to 140 ℉ .
    Best temperature for oil poaching is 160 ℉ , besides of taste and texture reasons , fish fillet should always be cooked to 140℉ to kill any parasites anyway .

    • mattwright March 15, 2011 at 2:56 am

      dionysos – freezing also does a good job of killing parasites. Good luck poaching your fish!