01 - Cut chicken breasts into thin strips measuring 1/2 x 2 inches. Pat thoroughly dry with paper towels and season evenly with salt and pepper.
02 - In a mixing bowl, whisk together flour, cornstarch, and baking powder until well combined.
03 - Lightly beat the egg in a separate bowl, then incorporate ice-cold sparkling water.
04 - Pour wet mixture into dry ingredients. Stir briefly with chopsticks or fork, leaving batter slightly lumpy—avoid overmixing for optimal crispiness.
05 - Heat vegetable oil in deep pan or fryer to 350°F.
06 - Dip seasoned chicken strips into batter, allowing excess to drip off, then carefully place into hot oil.
07 - Fry in batches for 3–4 minutes until golden brown and crispy, turning once halfway through. Avoid overcrowding the pan to maintain proper oil temperature.
08 - Transfer cooked chicken to wire rack or paper towel-lined plate to drain excess oil.
09 - Combine soy sauce, mirin, rice vinegar, sugar, and ginger in small saucepan. Heat gently until sugar fully dissolves, then cool to room temperature.
10 - Serve chicken tempura immediately while hot and crispy, accompanied by dipping sauce on the side.