Halve and core the napa cabbage. For each half, halve the cabbage again and cut into 1.5 to 2-inch chunks.

Place the chopped cabbage into a large bowl and rinse the cabbage well a few times to remove dirt or soil. Drain the cabbage and sprinkle in the sea salt. Toss the cabbage a few times with your hands to ensure the salt is sprinkled evenly on the cabbage.

Cover the cabbage and let it soak for 1 ½ hours, tossing the cabbage every 30 minutes. The cabbage should have wilted and shrunk in size.

Rinse the cabbage 3 times to remove excess salt. Drain well and place in a large mixing bowl. Set aside.

While the cabbage is soaking, make the porridge. Whisk glutinous rice flour and water in a small pot. Bring the mixture to a boil then lower the heat to a simmer. Cook until the mixture starts to thicken. Remove from heat and stir in the sugar. Set aside until the porridge has cooled to room temperature.

Combine the cooled porridge with hot paprika, fish sauce, garlic, onion and ginger. Stir well into a paste. Stir in chopped spring onion, carrot and radish.

Pour the Kimchi Paste over the cabbage. Wear a pair of gloves and use your hands to mix the cabbage thoroughly with the Kimchi Paste. Transfer the kimchi into a 1-litre air-tight container, packing it down.

Cover the container and let sit at room temperature for 1 to 2 days to start the fermentation. Open the container twice a day during the fermentation to release gas, and use a clean and dry spoon to press down the cabbage into the kimchi juices released by the cabbage, ensuring the cabbage is fully submerged into the kimchi juices.

After the fermentation, keep the kimchi in the refrigerator. To prevent kimchi smell from seeping into the refrigerator, fold 3 to 5 pieces of A4-size newspaper and place them at the bottom of a plastic bag. Place your kimchi container inside and tie it up tightly. Place the whole bag into another plastic bag and tie it up before storing in the refrigerator.

The kimchi can now be eaten or used in dishes, however, it will taste better after 1 more week of fermentation in the refrigerator. Always use clean and dry utensils to remove the kimchi from the container and keep them submerged in the kimchi juices.