For the dipping sauce, simmer ¾ cup of dashi, 3 tablespoons of soy sauce, 2 tablespoons of mirin, and 2 teaspoons of sugar in a small saucepan until the sugar dissolves.
Peel and devein 10 black tiger shrimp, leaving the tails on, and pat them dry.
Heat 1½in / 4cm of neutral oil in a pot to 350°F / 175°C.
For the batter, whisk 1 large egg with 200ml of iced water. Sift in 1 cup of all-purpose flour and mix briefly, leaving some lumps.
Dust the shrimp with potato starch and dip them in the batter. Fry a few at a time for about 2 minutes, until golden, then drain on a wire rack and serve with the dipping sauce.
