Cut the boneless chicken breasts into bite-sized pieces for even cooking.

In a mixing bowl, combine flour and baking powder. Slowly whisk in the cold sparkling water until smooth.

Heat vegetable oil in a deep pan over medium heat until shimmering.

Dip each piece of chicken into the tempura batter, allowing excess to drip off before frying.

Fry in batches until golden brown and crispy, about 4-5 minutes, then drain on paper towels.

Serve hot with dipping sauce on the side.