Seared Tuna with Smashed Cucumbers & Ume Vinaigrette

Seared Tuna with Smashed Cucumbers & Ume Vinaigrette

Bright, crunchy and so ready for a warm Summer night, this AIP recipe is satisfyingly savory and has a real umami hit from the ume vinegar. Ume vinegar is made from umeboshi, cured Japanese plums, and is a great agent in ramping up saliva production (which is an often-forgotten and hugely important part of our digestion!). Clients following an Autoimmune Paleo diet can’t eat any seeds, legumes, grains, dairy or nightshades, so I’ve used deep red sumac* powder in place of any seedy spices to crust the tuna. Sumac is a berry common in Middle Eastern cooking, and even grows right here in New England. *NOTE: If you’re still in the restricted phase of AIP, you may want to skip the sumac altogether.

Ume vinegar, mint, radish

Cook: 10 minutes

Prep: 15 minutes active

Serves: 4-6


  • 1.5 lbs cucumbers (Persian or Armenian work great)
  • 1 bunch radishes, trimmed and rinsed
  • 2 tablespoons ume plum vinegar
  • 3 tablespoons apple cider vinegar
  • 2" piece green garlic, minced OR 2 small cloves garlic, grated
  • 1.5" piece fresh ginger, peeled and grated
  • 3 scallions, thinly sliced
  • 2 sprigs fresh mint, torn
  • 1/4 olive oil or avocado oil
  • 2 lbs fresh tuna, cut into 4 steaks
  • 1/2 teaspoon sea salt
  • 2 teaspoons ground sumac
  • 1 tablespoon duckfat, or your preferred fat for cooking


  1. For the cukes: take your heaviest chefs knife and give the cucumbers a few good whacks, so that they crack right open. Then run your knife through them to chop coarsely. They'll be all wonky and strangely shaped—embrace the charm. Smash the radishes much like the cucumbers. Combine vinegars, scallions, cucumber and radishes in a medium bowl. Toss well and let marinate for 30 minutes, tossing after 15 minutes so it marinates evenly.
  2. While cucumbers are doing their thing, season fish with sea salt and sumac, rubbing seasoning into all sides of the flesh. Let stand to come to room temperature for 10-15 minutes (a good time to set the table, check some emails, or start a glass of wine, you know?)
  3. Heat a large non-stick skillet or cast-iron pan over medium high-heat. Once it's really hot, add 1 teaspoon or so of the duckfat (or your fat of choice). Swirl to coat, then add 2 pieces of the tuna. Sear for 45 seconds to 1 minute per side for rare, or up to 3 or 4 minutes per side for medium or fully cooked. This will also depend on how thick your tuna is, so keep an eye on it. Repeat with second round of tuna.
  4. Add mint and olive or avocado oil to cucumbers and toss. Serve tuna (either whole steaks, or sliced) with cucumber salad spooned over top, and garnish with more torn mint. Drizzle with extra sauce from cucumbers, optional.


Smashing the cucumbers and radishes is not only a great way to relieve stress, but it also helps them to absorb the flavor of the vinegars, garlic and ginger.

Make Ahead

This dish is best eaten the day you make it, but leftovers could be enjoyed the next day for lunch. Just make sure to keep it refrigerated, and opt to cook any fish intended for leftovers to a medium temperature (not rare).

Tools & Tips

Ask your fish monger to remove the skin and bloodline from your tuna. They can even cut it into steaks for you—just ask! You want tuna that is deep red, with little to no white stringy sinewy parts. You could absolutely serve this cucumber salad with seared halibut, salmon or even swordfish—just bump up the cooking time (as other fish you’ll want to cook through).