Pan-seared raw tuna fish with Wasabi Ponzu sauce
Very thinly slice the Shiso leaves and set it aside.
Heat oil in a frying pan over medium-high heat. Sear all sides of the fish until the color changes. Slice into 1/4 inch (6 mm) thick pieces and plate. Chill in the fridge for 30 minutes to 1 hour.
Combine the ingredients for the sauce in a bowl and mix well. Pour the sauce over the sliced tuna, then top with green onion and sesame seeds. Serve immediately.