Prepare fresh vegetables like bell peppers and broccoli or seafood such as shrimp and fish. Wash and cut the vegetables into bite-sized pieces.

In a deep fryer or heavy pot, pour enough oil to immerse the tempura pieces and heat to 350°F (180°C).

In a large mixing bowl, combine white rice flour, corn starch, a pinch of salt, and baking soda. Whisk thoroughly until well blended.

Create a well in the center of the dry mixture and crack in a large egg. Whisk gently while adding cold seltzer water until just smooth.

Dip each piece of vegetable or seafood into the batter and fry for 2-3 minutes until golden brown.

Transfer the fried tempura to a baking sheet lined with paper towels and let cool slightly. Serve hot with dipping sauces.