Kombu Squid Katsu Recipe

Prepare kombu brine

Wipe the kombu with a damp cloth to remove any surface dust (do not rinse vigorously). In a saucepan combine 600 ml water and the kombu and bring just to a simmer over medium heat; remove from heat before it reaches a full boil (small bubbles around edges). Let steep 10 minutes to extract umami, then remove the kombu and discard or reserve for another use.

To the cooled kombu liquid add 1 tablespoon kosher salt, 1 teaspoon sugar, 2 tablespoons sake and 1 teaspoon soy sauce. Stir until dissolved and cool to room temperature (if still warm, chill briefly). This brine will season and slightly firm the squid.

Prepare the squid: rinse under cold water, remove the head/innards if not already done, remove the transparent cartilage from inside the tube, and pat dry. Slice tubes into 1/2-inch wide rings or make a single flat cut to open the tube and flatten into a strip (for larger pieces). Keep tentacles whole or halved if large.

Place squid pieces in a shallow container and pour the cooled kombu brine over them so they are submerged. Cover and refrigerate for 30 minutes to 1 hour — no longer than 2 hours, as acid/salt will overly firm small squid. After brining, remove squid and pat very dry with paper towels (dryness is important for crisping).

Set up a three-station breading line: station 1 — mix the 3 tbs flour and 1 tbs cornstarch in a shallow dish and season lightly with a pinch of salt; station 2 — whisk 2 eggs with 2 tbs milk in a second shallow bowl; station 3 — place 1 cup panko in a third shallow dish (spread out to create a single layer).

Heat oil: pour about 500 ml neutral oil into a deep heavy skillet or pot to a depth of 1.5–2 inches. Heat over medium-high until the oil reaches 170–175°C (340–350°F). If you don't have a thermometer, test with a small breadcrumb — it should sizzle and brown in about 40–50 seconds.

Coat the squid: working in batches to avoid crowding, dredge each piece first in the flour/cornstarch mixture, shaking off excess; then dip into the egg wash, letting excess drip; finally press into panko to fully coat. If you opened tubes into strips, roll or use toothpicks to secure tentacles if needed.

Fry: Carefully lower coated squid pieces into hot oil and fry until golden brown and crisp, about 1.5–2.5 minutes per side for rings and 2.5–3 minutes for larger strips. Do not overcrowd the pan; fry in batches. Maintain oil temperature between 165–175°C by adjusting heat. Use a slotted spoon or spider to transfer cooked pieces to a wire rack set over a baking sheet to drain. This keeps the crust crisp; do not stack on paper towels for long periods.

If any pieces are thicker, finish in a 180°C (350°F) oven for 3–4 minutes to ensure cooked-through without burning the crust. Sprinkle with a pinch of salt immediately after frying and, if using, a few black sesame seeds as a subtle garnish.

Make the katsu sauce: in a small bowl combine 3 tbs ketchup, 2 tbs Japanese Worcestershire (or prepared tonkatsu sauce), 1 tsp soy sauce and 1 tsp mirin. Whisk until smooth and taste — adjust balance with a little more Worcestershire for tang or a touch more ketchup for sweetness.

Arrange: place shredded cabbage on the serving plate as a bed. Arrange the hot kombu-brined squid katsu on top. Serve with lemon wedges and the katsu sauce on the side for dipping.

Serve immediately while crisp. Leftovers lose crispness quickly; to re-crisp, reheat in a 200°C (400°F) oven for 6–8 minutes on a wire rack.