Ingredients

• 1/4 cup water
• 1 1/2 tablespoons red-wine vinegar
• 1 whole scallion, sliced thin, plus the green parts of 2 scallions, sliced thin
• 1 1/2 teaspoons minced peeled fresh gingerroot
• 1 1/2 teaspoons sugar
• 1 tablespoon soy sauce
• 1 tablespoon ketchup
• 1/4 teaspoon Asian (toasted) sesame oil
• 1 teaspoon cornstarch dissolved in 2 tablespoons water
• a 1-inch-thick halibut steak (about 1 pound), the skin and bone discarded and the fish cut into 3/4-inch pieces
• all-purpose flour seasoned with salt and pepper for dredging the fish
• vegetable oil for frying the fish
• cooked rice as a accompaniment

Instructions

1. In a saucepan simmer the water and the vinegar with the sliced whole scallion, the gingerroot, the sugar, the soy sauce, and the ketchup, stirring occasionally, for 5 minutes, add the sesame oil and the cornstarch mixture, stirred, and simmer the sauce, stirring, for 2 minutes. Keep the sauce warm, covered.
2. In a bag shake the halibut in the flour, transfer it to a large sieve or colander, and shake it to remove the excess. In a large deep skillet heat 1/4 inch of the vegetable oil over moderately high heat until it is hot but not smoking and in it fry the halibut in 2 batches, turning it, for 2 to 3 minutes, or until it is cooked through, transferring it as it is cooked with a slotted spoon to paper towels to drain. Add the halibut to the sauce, stirring to coat it well, and serve it over the rice and sprinkle with the scallion greens.