Hamachi Sashimi With Ginger Ponzu

Ingredients

  • 1 (25mm) square of kombu (dried kelp)
  • 2 tablespoons bonito flakes (shaved katsuobushi, also called hana-katsuo)
  • ½ cup shoyu (soy sauce)
  • ¼ cup freshly squeezed lemon juice (from 1 to 2 lemons)
  • ¼ cup freshly squeezed lime juice (from 2 to 3 limes)
  • ½ cup finely diced sweet onion, rinsed and drained well
  • 1½ teaspoons minced peeled fresh ginger
  • 1 tablespoon finely chopped fresh shiso (from 2 to 3 leaves)
  • 250g skinless hamachi (yellowtail) fillet
  • Flaky sea salt, such as Maldon
  • Extra-virgin olive oil (or lemon olive oil, see Tip)

Method

  1. Put the kombu and bonito flakes in a small bowl.

  2. Heat ¼ cup of water until steaming but not boiling. Pour the hot water over the kombu and bonito flakes. Let steep for 15 minutes.

  3. Add the shoyu, lemon juice and lime juice. Mix gently and let the ponzu sit for 2 hours at room temperature.

  4. Strain the ponzu through a fine-mesh sieve and discard the solids. Add the onion, ginger and shiso and mix.

  5. With a very sharp knife, cut the fish straight down or at a slight angle into 16 slices, each about ¼-inch thick.

  6. Transfer the sauce to a chilled plate with a lip, or a shallow serving bowl, making sure to evenly distribute the onions. Shingle the hamachi slices on top. Season the hamachi with some flaky salt and drizzle with olive oil.

TIP
  • To make lemon oil, gently poach lemon zest in olive oil, then let it steep for about an hour before straining.