Roasted Mustard Mackerel with Fennel Recipe

Longtime readers may remember the post I wrote about sustainable seafood a few years ago. The issue is still very much at the forefront of my mind, I carry around the pocket seafood guide issued in French by the WWF (check this list for your local equivalent), and I generally eat little fish — meaning both “not a lot of it” and “not very big ones”.

I’m not perfect, and although my conscience tells me I should give it up, we still go out for sushi (we like Enishi in the 18th) once in a blue moon — versus every week or two, as we used to in our oblivious days.

But when I buy fresh fish at the greenmarket, maybe once a month on average, it is usually one of two green-checkmark choices in the WWF guide*: either sardines, provided the poissonnier has filleted them, opening them up flat like tiny prayer books with tails, or mackerel.

My go-to cooking method for mackerel is to roast it in the oven, which is the simplest and most foolproof way to cook whole fish.

The mackerel I buy whole, and take up the fish guy’s offer to gut it for me. (“Gratté vidé ?” is the standard question you’ll be asked in a similar situation; “Oui, s’il vous plaît !” you’ll respond.). He also gives the option of keeping the heads on or having them cut off, Louis XVI-style, but to me a whole fish is a whole fish, and I’ve never been squeamish about my dinner looking me in the eye.

My go-to cooking method for mackerel is to roast it in the oven, which is the simplest and most foolproof way to cook whole fish.

Sometimes I’ll merely place the fish in a dish with a drizzle of olive oil and a glug of white wine, but my preference for mackerel goes to rubbing it with strong mustard, which heightens its flavor, and roasting it on a bed of vegetables.

The trick is to pick vegetables that will be ready in about the same time as the mackerel, and an excellent choice for that is fennel, sliced into shavings with a mandoline: as it cooks in the fish juices, it becomes tender and moist but still retains a little bit of snap. Fennel is a winning pairing for any fish, but its subtle aniseed notes work particularly well to round out the mackerel’s assertive flavor.

What’s your favorite way to prepare and cook mackerel?

* Provided they come from the northeast Atlantic; sardines from the Mediterranean are in the “not recommended” category. There is, however, new concern about the stocks of mackerel due to a dispute over fishing quotas between the EU and Iceland. Conservationists are now leaning toward an “eat occasionally” recommendation.

Roasted Mustard Mackerel with Fennel

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Roasted Mustard Mackerel with Fennel Recipe

Prep Time: 10 minutes

Cook Time: 20 minutes

Total Time: 2 hours, 30 minutes

Serves 2; the recipe can be doubled.

Roasted Mustard Mackerel with Fennel Recipe


  • 2 whole fresh mackerels, gutted
  • 2 teaspoons strong Dijon-style mustard
  • 2 sprigs of thyme, preferably fresh
  • 450 grams (1 pound) fennel bulbs, about 2 medium
  • 1 shallot, peeled (substitute a quarter of a medium onion)
  • fine sea salt
  • olive oil
  • 3 tablespoons white wine (substitute 3 tablespoons water)
  • steamed rice, for serving
  • lemon juice, for serving


  1. A couple of hours before you begin, rinse the fish under fresh running water, and pat dry. Spread each fish, inside and out, with a teaspoon of mustard. Place a sprig of thyme inside the cavity. Reserve in the fridge.
  2. Preheat the oven to 180°C (360°F).
  3. Trim the stems off the fennel bulbs and save in the freezer for your next stock-making session. Using a mandoline or a well-sharpened knife, slice the fennel very thinly. When you get close to the tougher core of the fennel, it may be harder to feed through the mandoline, so push it at an angle then, and be very careful not to slip. Slice the shallot thinly in the same fashion.
  4. Roasted Mustard Mackerel with Fennel
  5. Combine the fennel and shallot at the bottom of a baking dish that's large enough to accommodate the fish. Sprinkle with salt, and drizzle with olive oil and the white wine. Arrange the fish on top of the fennel.
  6. Bake for 20 minutes, until the fennel is cooked but still retaining a bit of crunch, and the fish is cooked through: to make sure, cut a slit through the thickest part of the fish down to the bone, and check that the flesh separates easily from the bone.
  7. Serve immediately, with rice and a touch of lemon juice.

Roasted Mustard Mackerel with Fennel

  • I love both mackerel and sardines, but, alas, have trouble digesting them! I agree about sustainably-caught fish, though, and tend to go for fish like pollock or salmon (if I want oily fish) or, better yet, trout. Farmed is not as nice as wild, but a lot kinder to the environment!

    • I love trout, too! We eat them in the Vosges, where my parents have a vacation house, as there is a guy raising trout in the valley down the road.

  • But mackerel don’t have scales do they?!

    They are good with rhubarb which is also in season now. Fish/fruit combinations are a bit risky but rhubarb’s not exactly a fruit. Gooseberries are, though, and they go with those too.

    • Excellent point about the scales. :) I guess I’m so used to the “gratté-vidé” phrase that I don’t stop to wonder whether scaling is needed?

      And I love the idea of pairing mackerel with fruit. I don’t think it’s commonly done in French cuisine (except lemon of course) but it must be wonderful. From what you suggest, it sounds like any acidic fruit would work?

      • Gooseberries were the traditional accompaniment to mackerel in British cuisine. I don’t think I’ve ever eaten them together, but Google brings up a plethora of recipes (as, indeed, it does if you Google “maquereau aux groseilles”.

  • I have that guide too, I try to adhere to it as much as possible, but it can be tough!…This mackerel recipe sounds delicious!…Thank you for sharing!…xv

  • I love mackerel, but despite living in the east end of London can’t seem to get any that hasn’t been cruelty pulverized by transport, I guess the ones from billingsgate market go elsewhere. I’m going to try this dish next time I have a bonfire and see what cooking it in the embers will achieve.

    • The thought of pulverized mackerel is indeed disheartening. Do report back on the bonfire — will you wrap the fish and fennel in foil then?

      • I would wrap it first in parchment paper and then the aluminium. However, I have used a similar roasting metod with lamb previously and used some clean straw in place of the paper, which worked well. A seaweed like kelp might work here and add something special.

  • sarah

    I love fennel! I want to try this asap. Today, coincidentally, I made trout in a new way that is now my new “favorite” way. I placed each trout in individual foil pockets (dressed with olive oil, salt, pepper, lemon slices, and tarragon). 10 minutes max in a 450 oven. Open pocket on your plate…it’s tender with lots of effortless yummy juice in each pocket. Would this work for mackerel too?

    • I do love the “papillote” method, as we call in in French, and don’t think of it often enough. I am, however, wary of cooking foods in foil because of the aluminum, so I usually use parchment paper.

  • Adele

    I’ve always been sort of scared of mackerel, but your recipe inspires me to give it a try.

    Very excited about a new option at work: sustainable fish shares! We’ve had CISA veggies available for several years through a Farm2Work program, and now Cape Cod Fish is coming with their sustainably caught fresh fish. Can’t wait to see what they bring, it will vary from week to week. Signed up for a 5-week program at first, to see how it works for us.

    • Lucky you, that sounds like a great system! I’d love to hear what you think if you’d like to report back sometime.

  • I’m in the same boat – we only eat sustainable fish, IF we eat fish. But it drives me nuts if you ask the fish monger at grocery stores where the fish is from and how its raised or if its sustainable. Half the time they dont know or you know they’re lying. I always go with my pocket reference too.

  • Susanna

    I adore mackerel, and I can’t wait to try this recipe. We have frozen mackerel from the Japanese market near us – do you think that would work well in the recipe?

    • Yes, I think it would! Is the frozen mackerel whole, or in fillets? If it’s the latter, it will take less time to roast, so I’d recommend you put the fennel in without the fish first.

  • While reading your recipe I was thinking of mackerel with rhubarb or gooseberries but I see others have beaten me to it! Anything slighly sour/tart goes well with mackerel as it cuts back the oiliness of the fish.

  • I agree with several other comments. First, mackerel is a little scary if you haven’t had much experience with it. Secondly, finding information regarding its origin can be tricky if not impossible (information you can trust, that is). The suggestions you offered are fantastic, thank you.

  • Wendy

    A favourite way of cooking mackerel here in Southeast Asia is to make a long slit on either side of the backbone and stuff the pocket with a spicy sambal: pounded or ground shallots, chilli, some dried shrimp paste, lemon grass too if you like. You can then grill the fish or fry them. Or simple slather the scaled whole fish with coarse salt and grill it as the Japanese do; scrape off most of the salt before eating if you have high blood pressure.

    • Sounds fantastic, Wendy, thanks for sharing!

  • Wow! It looks really great. I really loved it. Even though I am not a fish lover but I think it’s worth a try.

  • This makes cooking mackerel seem possible. Cooking a full fish has always intimidated me. I have never had mackerel but this sounds so good!

  • I love the use of mackerel, looks stunning. Although I have a hard time finding it where I’m at. Trout is fish we eat most frequently :)

  • candice

    Funny, that for you, little fish are good, but where I am, only bigger fish are eaten — all the local fisheries have minimum lengths, quotas, etc.

    In Louisiana, sardines come from cans. :)

    • Thanks Candice for pointing this out — I should have been more precise. What I meant was that I eat fish from species that are small (= they mature faster and reproduce sooner, which makes them more numerous and therefore less likely to be endangered), not small fish from large species, which should indeed be given a chance to grow and reproduce before they can be fished.

      And about the canned sardines that you find in Louisiana, are they fished from the Pacific? Is it typically noted on the can?

      • candice

        Sardines I’ve seen them canned from the north atlantic. Once, in a restaurant I had fresh ones, which were pacific-caught and really lovely.

        In general though, we eat local shrimp ($3-4/lb) and fish. Our fisheries in the state are managed such that the fish in danger aren’t allowed to be sold.

        (Or as in the case after the b.p. oil spill — all we had that summer were crabs because their habitat wasn’t reached. There was no fishing.)

  • Kristin

    Hi, what a lovely idea for cooking mackerel. I’ve heard that in the south of Norway it is typically served barbecued or grilled over a bonfire, then with rhubarb soup for dessert, though I’ve never tried it here in the North. Maybe a rhubarb soup on the side would be nice too?

    Thanks for sharing your excellent ideas and thoughts about food!

    • That sounds lovely, thanks Kristin!

  • Carol

    Was looking through old bob appetit magazines and stumbled across an article I had saved,d that you had done for them. Having just returned from a 2 week trip to Berlin, Paris and the south of France, it was a great read. AND then to turn on my phone and see your blog post was just weird!!!! The world works in strange ways. Can’t wait for the new cookbook. Congratulations.

    • Thanks Carol, that’s lovely to hear!

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