Seared Ahi With Grapefruit And Fennel

Seared Ahi with Grapefruit and Fennel.

Seared Ahi with Grapefruit and Fennel.

ahiMany of you know how much we like fennel here at the farm. Usually simply caramelized, or in risotto, fennel brings a light anise flavor and subtle, earthy sweetness to many dishes. We love it and think fennel is an underused and under-appreciated ingredient. So when we see a restaurant dish using fennel, we often try it out at home. And in this case, while in Kauai, we tried a dish of seared ahi with a light “slaw” of thinly sliced, barley pickled fennel and supremes of ruby-red grapefruit. It rocked, so we tried to make it at home.

ahi5ahi6ahi7And we are glad we did. Not only because it was a delicious dish, but it served as a reminder to us about what restaurant dishes we should try to cook at home. In general, we often avoid making restaurant dishes, they tend to be complex, use purposefully esoteric ingredients and are often cooked with equipment most home cooks just don’t have. But then there are restaurant dishes that simply combine quality fresh ingredients with a few basic techniques. The resulting dish seems upscale, and it is, but anyone can make the dish if they know a few tricks. This is one of those dishes.

ahi4ahi3All you need to make this dish is some very fresh ahi (and that may take some time to find, save this recipe for when you get it), a rocket-hot pan, a very sharp knife and some technique. The hot pan is to sear the seasoned ahi about 45-60 seconds per side (max). That is all you need, then slice the ahi to stop any cooking in residual heat.The sharp knife is to peel the grapefruit and cut “supremes” from between the membranes. This seems like a lot of work, but it takes just a few minutes and is easier than you think. Just do it over a bowl and reserve the juice. Then thinly slice the fennel (we add some radish as well). And if you have a small hand-slicer or mandolin, this gets even easier.

ahi8ahi9To finish the dish you simply make a quick pickle of the sliced fennel and radish. Quick pickling is one of the easiest ways to quickly add flavor to a dish, you just combine sugar and salt with sliced veggies for about 15 minutes then drain the veggies. We add a splash of rice wine vinegar here as well. Then you assemble the dish. Layer the grapefruit supremes and slices of the ahi and then add a splash of the reserved juice and a bit of rice wine vinegar. Then add the pickled fennel and radish. Season and serve. And the whole thing takes maybe 25-30 minutes.

ahi1And what do you get? A beautiful, flavorful and balanced dish that is pretty healthy, too. The light but meaty ahi goes very well with the acid of the grapefruit and the sweet, earthy crunch of the fennel and radish. It looks and tastes like a restaurant dish, but almost any home cook can make it.

ahi10Seared Ahi With Grapefruit And Fennel:

(Adopted from Bar Acuda in Hanalei, Kauai)

Notes before you start:

  • You can use most types of tuna for this dish, and you do not have to serve it as rare as we do. But tuna past medium-rare gets very dry. Tuna is expensive, so if you prefer well-cooked fish, other recipes may be a better choice.

What You Get: A restaurant-quality dish with less work than you think.

What You Need: No special equipment required, but a hand-slicer or mandolin is always nice for slicing veggies.

How Long? 25-30 minutes with 10 minutes of active time. This dish takes less time than you might expect. Anytime dish.


(Serves 4 as a starter, 2 as a main course)

  • 1 large or 2 small fennel bulbs, cleaned (a few fronds reserved)
  • 6 small radishes
  • 1 tablespoon sugar
  • 1 teaspoon salt
  • 1 teaspoon rice wine vinegar
  • 1 pound fresh ahi tuna (preferably cut into a rectangle by your fish monger)
  • Kosher salt
  • Freshly ground black pepper
  • 3 tablespoons high heat cooking oil like peanut or canola
  • 1 large ruby-red grapefruit


  1. Thinly slice the fennel and radish with a sharp knife or hand slicer. Place the fennel and radish into a bowl and mix in the sugar and salt. Let sit for 15 minutes, then drain any liquid. Taste and adjust seasoning and then add the rice wine vinegar. Set aside.
  2. Place a heavy skillet or cast iron pan over high heat and let it get very hot. Turn on your kitchen fan. Meanwhile, liberally coat the ahi with salt and pepper and then rub on 1 tablespoon fo the oil. When the pan is very hot add the rest of the oil, then the ahi and sear for 45-60 seconds on each side. Turn using tongs or a spatula. When each side is seared, remove the ahi from the heat.
  3. Take one slice of the ahi and look at doneness. If ready, slice immediately into 1/2 inch slices. If you want the ahi to cook a little more, simply wait 30-60 seconds. The ahi will cook in the residual heat. Then slice and set aside.
  4. Over a bowl, peel the grapefruit and then cut supremes of the flesh from between each membrane. Place the slices in the bowl and then squeeze out any juice into the bowl.
  5. To assemble the dish, place alternating layers of grapefruit and ahi across a plate. Season and drizzle on some of the reserved juice and vinegar from the pickles. Add on the pickled fennel and radish. Top with a few fennel fronds and a big grind of black pepper. Serve.

30 thoughts on “Seared Ahi With Grapefruit And Fennel

  1. Stunning. And I’ve really been looking for a new way to incorporate some fennel in with my seafood. It’s a very distinct flavor sometimes, but this seems like the perfect pairing.

    • Thanks. The seared Ahi does go well with the sweet/sour of quick pickled fennel, radish, daikon or cucumber. Think of these as lighter versions of the pickled ginger matched with sushi…

    • Hi. It is worth doing at home, just a hot pan and you are ready to go. And the method of cooking to rare and then letting it cook until you like the doneness and slicing also works really well.

  2. This looks so pretty and fresh, and the flavor combination sounds like it works.
    Good for you for re-creating a fancy restaurant dish at home, and deconstructing the process to take the mystique out for the rest of us!
    I’ve got a hot pan, a sharp knife (and a Benriner) and I feel like, if I had fresh ahi and fennel, I could make this, too.

  3. That looks SO good! What an amazing combo: tuna with grapefruit!
    And to drink with it? I’d say: prosecco, blueberries (sliced in half), brown sugar and raspberries (crushed).

  4. Pingback: Squash, Fennel and Potato Bake - Can't Stay Out Of The Kitchen

Please Comment

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s