Step 1

Cut the vegetables into ½ cm / 1/8 in slices or ½ cm / 1/8 in wide matchsticks.

Step 2

Spread some flour on a large plate to coat the vegetables in later. Prepare two fairly large glass or metal bowls. One should be a bit larger than the other so that you could nest the smaller bowl inside the larger one.

Step 3

In a separate bowl, combine sifted cornflour, rice flour and baking soda.

Step 4

In another bowl, combine all dipping sauce ingredients and set aside until later.

Step 5

Pour oil into a small pot and set it on the stove on a medium heat. Allow it to come to temperature (170-180° C / 340-360° F) while you prepare the batter.

Step 6

Place ice cubes at the bottom of the large bowl. Rest smaller bowl on top of the ice cubes. Put cold aquafaba into the small bowl and whisk it with a hand whisk until frothy. Add fridge cold sparkling water to the aquafaba, then mix in cornflour, rice flour and baking soda with a hand whisk to achieve a runny (crepe-like) batter. If using a flour with gluten as opposed to rice flour, be very careful not to overmix the batter or else your batter will end up heavy. Mix in very gently with a pair of chopsticks and ignore any lumps you may end up with - tempura batter made with gluten flour should be lumpy.

Step 7

Drag each piece of vegetable in a little flour first and then immerse it in cold batter.

Step 8

Once the oil comes to temperature, test it by dropping a piece of tempura in it. If the tempura drops to the bottom but comes up right after that, the oil is at the correct temperature. If the vegetables do not drop to the bottom at all, the oil is too hot. Depending on the size of your pot and vegetables, fry 2-3 pieces at a time. It is important not to overcrowd the pan or else you'll end up with greasy tempura.

Step 9

Cook tempura for 1-2 minutes (depending on thickness and hardness of the vegetables - courgette cooks quicker than butternut squash, for example) and then turn and cook for another 1-2 minutes - until both sides are lightly browned. Once they achieve the desired colour, fish them out with a slotted spoon and place them on a piece of paper towel to drain any excess oil.

Step 10

Serve straight after frying with a dipping sauce on the side.