Cut the radish into medium sized cubes. Put the cubed radish into a large mixing bowl and add the sugar and the salt and mix them well. Leave it for 1 hour at room temperature.
While waiting, chop the green onion into small pieces and make the Kimchi base. Blend the onion and apple with the fish sauce in a blender. Make the rice porridge by mixing the water and the rice flour in a bowl and heating them up for 1 min in a microwave. Mix all the Kimchi base ingredients (except for 2 Tbsp of Korean chili flakes) in a medium sized bowl.
After one hour, rinse the radish in cold running water a couple of times and drain any excess water for 5 mins.
Put the radish into a clean mixing bowl and add 2 Tbsp of Korean chili flakes. Mix the chili flakes with the radish evenly. Add the chopped green onion and the Kimchi base and mix them evenly and thoroughly.
Move the seasoned radish into an air tight glass container and leave it at room temperature for between 6 to 24 hours depending on the temperature. After that keep it in the fridge.
