This is a no-cook tuna tartare built around sushi-grade tuna, a wasabi-spiked Kewpie mayo, and a handful of pantry staples. The whole thing comes together in 25 minutes, and the result is a light, protein-packed dish that works as a starter or a standalone meal when you want something satisfying without turning on the stove. The flavors are bold enough to hold their own without any fuss.
What makes this version work
Two things matter most here. First, the tuna needs to be cut small and uniform — roughly ¼-inch dice. Uneven chunks mean some bites are overwhelmed by the mayo while others taste plain. Take the extra two minutes to be consistent with your knife. Second, the wasabi mayo gets made separately and folded in at the end rather than mixed directly into the tuna bowl. This keeps the seasoning even and lets you taste and adjust the heat before it touches the fish. The ginger goes into the mayo, not the tuna, so it distributes evenly through every bite instead of clumping in one spot.
Ingredient notes
- Sushi-grade tuna: This label means the fish has been handled and frozen to FDA guidelines for raw consumption. Buy it from a fishmonger or a grocery store with a dedicated fish counter — not from a standard pre-packaged case. If you can’t find it locally, a reputable online seafood supplier ships it frozen and it thaws well overnight in the fridge.
- Kewpie mayonnaise: It’s made with egg yolks only and rice vinegar, which makes it richer and slightly tangier than standard American mayo. Most Asian grocery stores carry it, and it’s increasingly available at mainstream supermarkets. In a pinch, regular full-fat mayo works, but add an extra ¼ tsp of rice vinegar to compensate.
- Wasabi paste: Most tubes sold in Western supermarkets are horseradish-based with green coloring — that’s fine for this recipe. Pure wasabi is more expensive and the difference is subtle once it’s blended into mayo.
- Toasted sesame oil: Don’t swap this for plain sesame oil. The toasted version has a much deeper, nuttier flavor and that’s what the recipe is built around.
Make-ahead notes
The wasabi mayo can be made up to 3 days ahead and kept covered in the fridge — the flavor actually improves after a few hours. The tuna, however, should be diced and dressed no more than 2 hours before serving. Raw fish breaks down quickly once it’s cut and seasoned, and the texture gets soft and unpleasant if it sits too long. Do not freeze the assembled tartare. If you’re prepping for a dinner party, dice the tuna and keep it plain and covered in the coldest part of your fridge, then fold in the mayo and soy mixture right before plating.
What can go wrong
- The tartare turns watery on the plate: This happens when the tuna isn’t patted dry before dicing. The fish releases moisture once it’s cut. Blot it firmly with paper towels before you start chopping.
- The mayo overwhelms the tuna: Start with about two-thirds of the mayo mixture and fold it in gradually. You want the tuna coated, not swimming. Add more only if needed — skip the instinct to dump it all in at once.
- The mold shape collapses when you lift it: Pack the tartare firmly into the mold and chill the plated mold in the fridge for 10 minutes before removing it. A warm or loosely packed mold won’t hold.
- The wasabi heat is uneven: Wasabi paste can clump if you don’t whisk the mayo mixture thoroughly. Make sure it’s fully smooth before it goes anywhere near the tuna — a small whisk or a fork works better than a spoon here.
- The dish tastes flat: Low-sodium soy sauce is mild by design, so taste the dressed tuna before plating. A few extra drops of soy or a small pinch of flaky salt right before serving can fix a dull batch fast.
Japanese Wasabi Mayo Tuna Tartare
Ingredients
Main Ingredients
- 300 g sushi-grade tuna finely diced
- 2 tbsp soy sauce low sodium preferred
- 1 tbsp sesame oil toasted for depth
- 1 tbsp finely chopped scallions green parts only
Wasabi Mayo
- ¼ cup mayonnaise Japanese Kewpie for authenticity
- 1 tsp wasabi paste adjust to heat preference
- 1 tsp rice vinegar adds brightness
- 1 tbsp finely grated ginger freshly grated
Instructions
- Begin by preparing the wasabi mayo. In a small bowl, whisk together the 1/4 cup of Japanese Kewpie mayonnaise, 1 teaspoon of wasabi paste, and 1 teaspoon of rice vinegar until smooth. Adjust the wasabi to your heat preference.
- In a separate larger bowl, combine the finely diced 300g (10.5oz) of sushi-grade tuna with 2 tablespoons of low sodium soy sauce, 1 tablespoon of toasted sesame oil, and 1 tablespoon of finely chopped green scallions.
- Gently fold the wasabi mayo into the tuna mixture until evenly coated. The aroma of the sesame and the sharpness of the wasabi should be enticing.
- Place a circular mold on a serving plate and fill it with the tun mixture to create a neat round shape. Carefully remove the mold for an elegant presentation.
Notes
Nutrition
FAQ
Is it actually safe to eat raw tuna at home?
Yes, as long as you use sushi-grade tuna from a reputable source. Sushi-grade fish has been frozen to temperatures that eliminate parasites, which is the main safety concern with raw fish — this is different from standard raw fish at the meat counter, which is not intended for raw consumption.
Can I use canned or cooked tuna instead?
You can, but the dish becomes something different — more of a tuna salad than a tartare. The silky texture that makes this recipe worth making comes specifically from fresh raw sushi-grade tuna, and no cooked substitute replicates it.
What do I serve this with to make it a full meal?
Steamed short-grain rice is the most straightforward option and turns four appetizer portions into two solid meals. Wonton chips, cucumber slices, or crispy rice cakes also work well and add some crunch without competing with the flavors.