Wipe off the excess moisture from both sides of the tuna block. Lightly season with salt and pepper (both sides.)
Mince the leek, garlic, and ginger and set aside. Combine the ● ingredients.
Thinly slice the onion. If it's spicy, soak in water. Lightly rinse the radish sprouts and then cut into 2 cm pieces.
Heat vegetable oil in the frying pan and cook the ☆ ingredients, being careful not to burn them, until fragrant.
Once fragrant, add the combined ● ingredients. Bring to a boil and then turn off the heat. This completes the onion sauce.
Next, heat some vegetable oil in a separate frying pan and pan-fry the tuna block until both sides are lightly browned.
Once done, slice into your preferred sizes.
Arrange the sliced onion on a plate and place the tuna from Step 7 on top. Scatter with lots of radish sprouts and then pour on lots of onion sauce from Step 5 to finish.
Since I didn't have any radish sprouts on this occasion, I used mizuna leaves.
Story Behind this Recipe
The garlic & butter fried sea bream that I had at a sushi restaurant was so impressive! It was a mix of Japanese style with a touch of Western style, so using that idea, I used a tuna block and turned it into something other than the normal sashimi, adding a touch of Western style, and it came out really delicious.
Cook the tuna rare. If you cook it too much, it will become difficult to slice.