Prepare all of your vegetables prior to starting the recipe. 

In a medium bowl, whisk together the flour, potato starch, and baking soda. Set aside.

In a large bowl, stir together the egg and club soda.

Stir the flour mixture gradually into the egg mixture just until combined. Don’t overmix. It’s okay to have a few lumps. The mixture should be pretty thin,

In a large, heavy bottom pot or Dutch oven, heat the oil to 350 degrees.

Once the oil reaches 350 degrees, dip the vegetables into the batter, shaking off any excess batter back into the bowl.

Carefully drop them, a few at a time, into the hot oil. Don’t add too many at one time or the oil temperature will drop and the tempura will be oily instead of crisp.

Cook for 2 ½ minutes, then flip, and cook another 2 ½ minutes until golden brown.

Use a wire spider or slotted spoon to remove the vegetables from the oil. Allow the vegetables to drain for a few seconds, before placing them on a paper towel-lined plate.

Repeat with the remaining vegetables and batter.