Cut the Chinese cabbage in four, then slice into 3-cm slices. Place in a bowl with cold water and salt and allow to stand for at least two hours.
Prepare the dough by heating the rice flour with 100 ml of water. Beat thoroughly with the mixer to incorporate well and avoid lumps. Take off the heat and allow to cool. Transfer to rice flour dough to a bowl. Add the chilli pepper, garlic, apple, onions, and chopped radishes, and mix.
After the cabbage has been in soak for the required time, remove from the brine, wash well, and rinse in cold water. Then, add it to the other ingredients (ideally, the ingredients should be placed between cabbage leaves, folding them to create small pockets).
Start the fermentation process: place the mix of cabbage and vegetables in a sterilized jar that has an airtight lid. Fill the jar right up, pushing the vegetables down. Allow to stand for at least three days until small bubbles begin to form; that way, you'll know that fermentation is taking place. Kimchi can be stored in the fridge for around four weeks.
Serve the kimchi garnished with the green part of a leek cut into strips and with the vegetable patties.
* The traditional Korean chilli used in this dish is called gotchugaru, flaked red chilli pepper.