Step 1: Prepare Shrimp : Peel and devein large shrimp, leaving tails on. Pat dry with paper towels and lightly season with salt.

Step 2: Make the Batter : In a bowl, mix all-purpose flour, cornstarch, and baking powder. In another bowl, lightly beat egg with ice-cold water. Gently combine wet and dry ingredients to make a lumpy batter. Keep cold.

Step 3: Heat Oil : Heat vegetable oil in a deep fryer or heavy pot to 350°F (175°C). Use enough oil to fully submerge the shrimp.

Step 4: Fry Shrimp : Dip shrimp in batter, allowing excess to drip off. Fry 2–3 shrimp at a time until golden and crispy, about 2–3 minutes per batch. Do not overcrowd the pan. Drain on paper towels.

Step 5: Prepare Dipping Sauce : Combine dashi, soy sauce, mirin, and sugar in a saucepan. Heat until sugar dissolves. Optionally, add grated daikon radish.

Step 6: Serve : Plate tempura shrimp immediately while hot and crisp. Serve with dipping sauce on the side.