Chase Kojima’s Tuna Tataki

Recipe Information

Preparation time
1-2 hours
10 minutes


  • Binchotan charcoal (see note below)
  • 70 gm piece sashimi-grade tuna
  • 50 gm White pickled ginger in juice
  • 30 gm mixed micro herbs, such as shiso, mâche and colourful edible flowers

For the shiitake sauce:

  • 30g caster sugar
  • 1½ tbsp soy sauce (see note)
  • 2 tsp sesame oil
  • 2 tsp mirin
  • 1 garlic clove
  • ½ tsp freshly ground black pepper
  • 2 shiitake mushrooms, coarsely chopped, stems discarded
  • 10ml nashi pear juice

For the pickled asparagus:

  • 1 asparagus spear, peeled
  • 1 white asparagus spear, peeled
  • 50ml yuzu juice (see note)

For the pickled enoki:

  • 30g enoki mushroom, trimmed in half
  • 36ml white soy sauce (see note)
  • 80ml (1/3 cup) grapeseed oil
  • 2 tsp lime juice

For the smoked ponzu:

  • 2 tbsp soy sauce (see note)
  • 1 tbsp A-grade bonito flakes (katsuobushi)
  • 60ml (1/4 cup) rice vinegar (shiragiku)
  • 1 tbsp grapeseed oil

For the burnt leek aioli:

  • 100g leek (white part only, about 5cm long)
  • 1 tbsp grapeseed oil, for brushing
  • 6g (1/4 size of a carrot, chopped) carrot
  • 6g (1/8 size of a small onion, chopped) Small onion
  • 0.3 tsp sake
  • 1 ¾ tsp soy sauce (see note)
  • 1 tsp mirin
  • ½ tsp rice vinegar (shiragiku)
  • 1 tsp white miso paste
  • 1 tsp lemon juice
  • 1 garlic clove, crushed
  • 100g mayonnaise (Best food Brand Mayo, or any real mayonnaise)
  • 0.4 tsp xanthan gum powder (see note)


  1. Preheat charcoal until hot. Brush tuna with grapeseed oil, season with salt and pepper, then sear each side over charcoal (Each side no more than 20 seconds on high heat). Refrigerate until chilled.
  2. For shiitake sauce, blend soy, sugar, sesame oil, mirin, garlic, black pepper and 3 tsp water blend until smooth. Transfer to a small saucepan, add mushroom, bring to the boil, then simmer for 5 minutes. Cool to room temperature, then add nashi juice. Set aside.
  3. For pickled asparagus, blanch green asparagus in salted boiling water (30 seconds). Refresh in iced water, drain and pat dry. Halve both green and white asparagus and trim each half to 4cm long, then cut lengthways into four sticks each. Just before serving, pickle in the yuzu juice (1 minute).
  4. For pickled enoki, combine soy, oil and lime juice in a bowl and mix until emulsified. Just before serving, pickle the enoki in mixture (5 minutes).
  5. For smoked ponzu, bring soy to a simmer in a small saucepan, then remove from heat. Add bonito flakes and stand for 10 minutes. Strain, discarding bonito. Add vinegar and oil and mix well. Just before serving, marinate the seared tuna in the smoked ponzu (5 minutes).
  6. Blend pickled ginger and Xanthan Gum Powder together to reach a gel consistency. Set aside.
  7. For burnt leek aioli, brush leek with oil and grill over charcoal or on a grill plate, turning occasionally until outer layer is completely charred and burnt like ash (On low heat approximately one hour until leek is completely charred). Scrape ash into a mortar and pestle and pound to a fine powder. Set aside. Blend remaining ingredients (except mayonnaise and xanthan gum) in a blender until very smooth. Transfer to a bowl, then add mayonnaise and stir to combine. Spoon one-quarter of the mixture into a blender, add leek ash powder to taste (you may not need all) and xanthan gum powder, and blend until thick, then add remaining mixture and blend until thick mayonnaise consistency.
  8. To serve, spread aioli in a 4cm square in the centre of a plate and blowtorch the aioli to bring the flavour out. Slice tuna into six pieces and arrange on top. Arrange shiitake, enoki, and asparagus around, fill the gaps with herbs and flowers. Place about six dots of ginger gel around the tuna, and drizzle smoked ponzu over.

Tips and notes from Chase:

  • Binchotan charcoal is a clean-burning Japanese charcoal, which is available from Asian grocers and barbecue stores. If you don’t have a charcoal barbecue, you can sear the tuna in a hot pan or and char the leek over a gas flame.
  • Use Yamasa brand soy sauce and Higashimaru brand white soy sauce, where available from Japanese grocers.
  • Xanthan gum can be ordered online or is available from speciality cooking shops.
  • Do I need to make the smoke the ponzu? Yes, please use the smoke ponzu on the recipe instead of just buying ponzu. (The smoked flavour comes from the Katsuoboshi flakes)
  • What do I do if the quantity seems very small and there’s not enough in the blender for the leek sauce base? Depending on your blender, if the volume is too little to get the right consistency feel free to double the ingredient amount for the burnt leek aioli.