Lightly crush the cucumber with a rolling pin until it begins to crack. Slice thinly.

Peel the mooli and dice as finely as possible.

Finely slice the spring onions.

Peel the carrot and use a peeler to create long ribbons.

In a bowl, combine the rice vinegar, caster sugar, gochugaru and sea salt. Stir until the sugar and salt have dissolved.

Add the cucumber, mooli, spring onion and carrot.

Mix thoroughly to coat all the vegetables in the pickling liquid.

Cover and refrigerate for at least 20 minutes before serving.