Prepare all the vegetables and set them aside.

In a large bowl, mix cold water, beer, and ice cubes.

In a separate bowl, combine cake flour and cornstarch.

Gradually mix dry and wet ingredients together, whisking until smooth. Add the egg and whisk again until well incorporated.

Pour the cold batter into the vegetable mix and combine everything thoroughly.

Heat vegetable oil in a pan to 170-180°C (340-360°F).

Fry the battered vegetables in small batches until golden brown and crispy.

Drain on a wire rack to maintain crunchiness. Serve immediately with a dashi-based dipping sauce.