Tuna Tataki Recipe

Prepare the onions: peel and very thinly slice the red onion into half-moons. Place slices in a heatproof jar or bowl.

Make the pickling liquid: in a small saucepan combine rice vinegar, water, sugar, salt, and optional red pepper flakes. Warm gently over medium heat, stirring until sugar and salt dissolve (about 1–2 minutes). Do not boil.

Pour the warm pickling liquid over the sliced onions so they're fully submerged. Let cool to room temperature, then cover and refrigerate at least 20 minutes (best 1 hour) before serving. Will keep refrigerated for up to 1 week.

Toast seeds and nuts (if not already toasted): in a dry skillet over medium heat, toast the 3 tbs sesame seeds and 2 tbs peanuts/pine nuts until fragrant and lightly golden, 2–3 minutes. Watch carefully and stir frequently. Let cool slightly.

Blend the pesto: in a small food processor or blender combine shiso leaves, cilantro (if using), toasted sesame seeds, toasted nuts, garlic clove, soy sauce, rice vinegar, lime juice, and salt and pepper. Pulse to a coarse paste.

Emulsify: with the processor running, slowly drizzle in the 3 tbs neutral oil and 1/2 tsp toasted sesame oil until incorporated and the pesto reaches a spoonable but slightly loose consistency. Taste and adjust salt, acidity, or oil to preference. Transfer to a small bowl and refrigerate until ready to use. Yield: about 3/4 cup.

Prepare the tuna: pat the tuna loin dry with paper towels. Season all over with 1 tsp fine salt and 1 tsp black pepper.

Press on sesame crust: on a small plate combine black and white sesame seeds. Lightly brush or rub the tuna lightly with the 1 tbs neutral oil so seeds adhere. Press all sides of the tuna into the sesame mix to coat evenly; ensure the four sides are coated but the top and bottom can be lightly coated as desired (tataki style leaves most of the interior raw).

Sear the tuna: heat a heavy skillet (cast iron or stainless) over high heat until very hot. Add a thin film of neutral oil. When shimmering, sear the tuna on each of the four sides for 15–25 seconds per side — you want a deep, quick sear on the crust while keeping the center rare. For a thicker loin you may sear top and bottom briefly as well; total sear time should be about 60–90 seconds. Do not overcook.

Rest and slice: transfer tuna to a cutting board and let rest 2 minutes. Using a very sharp knife, slice tuna thinly on a bias into 1/8–1/4 inch slices. Clean the knife between long runs for neat slices.

Plate the tataki: spread small dollops (about 1 tsp each) of shiso-sesame pesto on your serving plates or smear a thin line with the back of a spoon where the tuna will rest.

Arrange tuna slices in an overlapping fan over the pesto. Distribute pickled red onions over and around the tuna.

Finish: sprinkle the sliced green onions and microgreens or shiso leaves over the tuna. Drizzle 1–2 tsp ponzu or a little light soy sauce across the slices (or serve on the side). Squeeze a small wedge of lime over each portion to taste.

Serve immediately so the tuna remains rare and the sesame crust stays crisp. Leftover sliced tuna can be refrigerated up to 1 day, but is best fresh.