For the sweet and sour sauce: Combine pineapple juice, brown sugar, vinegar and ginger in a pot and boil until sugar dissolves. Strain and remove ginger from the mixture. Return to the pot over reduced heat. Whisk together the cornstarch with 1/4 cup water, then slowly whisk cornstarch slurry into sauce and cook until sauce thickens.
For the ahi belly: Sprinkle salt and pepper on fish.
Whisk tempura flour with a pinch of salt and pepper, then add soda water until evenly mixed.
Coat fish with all-purpose flour, then fully immerse fish into tempura batter.
Bring oil to 350 degrees F in a deep-fryer.
Fry fish until golden brown, about 5 minutes.
Meanwhile, saute bell pepper, pineapple and green onion in a pan with a drizzle of oil.
Top fish with 1/2 cup sweet and sour sauce and the pineapple mixture. Sprinkle with furikake, if using. Serve with rice.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Umekes Fish Market Bar and Grill, Kailua-Kona, HI