Tataki—seared Bonito fillet with onion sauce

Every spring, my 81 year-old mum makes a big batch of onion sauce and keeps it in a large jar in the fridge. We use it all summer long as it is an excellent marinade. Favorites include deep-fried whole fish such as small sized Aji or Japanese Horse Mackerel, and chiayu baby sweet fish. It also pairs well with deep-fried chicken thigh meat. Or pour it over hiya yakko freshly made tofu and served chilled. You can use this multi-purpose sauce as salad dressing or as a topping for grilled fish. In today's recipe, we will dress it over Tatakiseared Bonito fillets.

The Bonito is a long-distance swimmer that begins its voyage from the south of the Pacific Ocean. The fish swims along with the Kuroshio current, a warm and fertile current traveling up the coast of Japan as far north as Miyagi prefecture. Modori Gatsuo, returning Bonito, is the name for the same fish that has swam all the way from the south in early summer and has reached the colder water off the coast of Miyagi. It then turns around and travels back south in late summer. By that time, the fish is plump from eating oily sardines during the summer months. Hence, the returning Bonito is packed with lots of healthy omega 3 oils that we need to rejuvenate our body fatigue from the summer heat. It is also very, very, very tasty!

For this recipe you can use any Bonito available locally. But, be sure to keep modori Gatsuo in mind if you are traveling to Japan in late summer!

Today, we will be gently searing the fillet, producing sear marks on the outside. As pictured, the centre will remain red and raw. Be careful not to overcook the fish on the open flame! A minute or two on each side will do the trick.  

Okay, let's get started!

Seared Bonito fillet with onion sauce 叩き

Serves 4

Onion Dressing Sauce


  • 2 onions peeled and sliced finely
  • 3 tablespoons sugar
  • 2 teaspoons salt
  • 150ml apple vinegar (or rice vinegar or kurozu dark vinegar)
  • 150ml soy sauce
  • 150ml E.V. olive oil


  1. Air out sliced onions by spreading them on a large tray and leaving them for 15 minutes.
  2. Combine the remainder of the ingredients and marinate the sliced onions overnight. The dressing sauce will be ready for use the following day.

TatakiSeared Bonito Fillet


  • 1/4 fresh Bonito fillet with skin
  • salt as needed
  • olive oil as needed
  • white wine or sake as needed
  • 4 oba leaves (or fresh dill)
  • 2 cloves garlic, thinly sliced and toasted
  • assorted green leaves (rocket shoots, watercress, daikon sprouts, or soba sprouts)
  • 8 asatsuki-negi shallots finely chopped
  • 40g salted wakame (sea weed, what I call sea lettuce, rinsed and cut in bite size)
  • 1 tomato, cut in half and sliced
  • 1 hana-myoga (ginger lily), rinsed and finely chopped (optional)


  1. Rinse the fillet in cold salted water and pat dry. When filleting a whole sashimi-quality fish yourself, skip this step.
  2. Place the fillet, skin down, on a cutting board and weave four or five metal skewers, width-wise, 5mm deep into the skin side of the fillet (as pictured above).
  3. Salt the fillet generously.
  4. Place the fillet, skin down, over a gas flame or on a BBQ and sear for about 30 seconds.
  5. Turn over and sear the red flesh side for about 30 seconds. Both sides of the fillet should have grill marks and the center should remain red and raw.
  6. Dunk into icy cold water, drain and dry.
  7. Cut the seared fish fillet into 5mm thick slices and arrange them on a plate with fresh green leaves, wakame (sea weed), chopped hana-myoga, roasted garlic, and sliced tomatoes.
  8. Pour the dressing sauce over the dish and sprinkle chopped asatsuki onion or chopped shallots.

I hope you enjoyed preparing, and more importantly, eating this refreshing summer dish. Join me next time and learn to cook Kuwayaki Hervey Bay Scallops and my signature BBQ sauce, which you can use on everything from seafood to chicken!

copyright © 2015 Shuji Ozeki