Japanese Grilling Over Rice Straw Katsuo No Tataki and Karataki Searing Methods

Ingredients

• 600 g katsuo (skipjack tuna), dorsal fillet, skin-on, very fresh — no fishy odour
• 1 tsp salt
• For the searing
• 1 large bundle inawara (dried rice straw), or blow torch for karataki method
• 4 long metal skewers, for impaling the fillet
• For the ice shock
• 2 litres water, ice-cold, with abundant ice
• Tosa condiments
• 6 cloves garlic, thinly sliced
• 30 g fresh ginger, finely grated or julienned
• 4 myoga, thinly sliced
• 4 stalks green onion (negi), finely sliced
• 8 leaves shiso, whole or torn
• 80 g daikon, finely grated
• For the sauce
• 80 ml tosa-joyu, Kochi-style concentrated soy sauce with dashi; kaeshi-style, stronger and darker than standard soy

Method

1. 1
   Select the dorsal fillet of a very fresh katsuo. Pat the surface completely dry with kitchen paper — no moisture must remain on the skin or flesh. Impale the fillet lengthwise on two or three long metal skewers so it is held flat and secure. The surface must be visibly dry to the touch before any flame is applied.
2. 2
   Traditional method: Set a bundle of dried inawara (rice straw) alight in a trough or heatproof vessel. Hold the skewered fillet skin-side down over the burning straw. The straw burns at 600–800 °C but only for 30–60 seconds; work within this window. Rotate the fillet to expose all exterior surfaces to the flame. Total searing time is 90 seconds to 3 minutes depending on desired char depth. The fillet is done when the skin and outer flesh are visibly charred and fragrant — carrying the specific hay-and-grain smokiness of inawara — while the bulk of the flesh remains cold and raw beneath. Karataki (blow-torch) method: hold the torch 10 cm from the surface; char each face for 30–60 seconds. The goal is the same — defined surface char, raw interior. This is where the dish lives or dies: insufficient searing gives no char; excessive searing cooks the interior; wrong fuel gives wrong smokiness.
3. 3
   Remove the fillet from the flame immediately. Plunge it completely into the prepared ice-water bath and submerge for 30 seconds. The flesh will firm perceptibly under the hand. Remove, pat thoroughly dry. Without complete ice-water shocking, residual heat penetrates the interior and the intended raw character of the dish is lost.
4. 4
   Slice the shocked fillet thickly — approximately 1 cm slices — across the grain. Arrange the slices overlapping on a serving plate. The cut face should show a clear contrast: a thin charred and seared outer band of brown-grey against a deep red-pink raw interior.
5. 5
   Lay condiments over the slices in sequence: green onion first, then ginger, then myoga, then garlic, then shiso. Place grated daikon alongside. The Tosa tradition mandates an abundance of aromatic garnishes — far more than any other sashimi presentation. Pour tosa-joyu over the top directly before serving. Press or slap the condiments lightly into the fish slices in the tataki manner before eating.