Prepare the Cabbage: Cut Napa cabbage into bite-size pieces.
Make Rice Flour Porridge: Mix water and sweet rice flour in a pot. Stir continuously for about 5 minutes on medium heat until it thickens. Lower the heat, add sugar, and mix well.
Blend Seasonings: Blend garlic and fish sauce (or additional salt for a vegetarian version) to make the Kimchi paste.
Cool the Porridge: To cool the porridge quickly, place the pot in cold water.
Mix Paste with Hot Pepper Flakes: Combine the cooled porridge with hot pepper flakes.
Prepare Optional Seafood: If using, prepare the squid by cleaning, salting, and refrigerating it a week in advance. Rinse before use.
Mix Vegetables with Paste: Combine leek, green onions, and optional squid with the Kimchi paste.
Final Mixing: Thoroughly mix the paste with the prepared Napa cabbage. Ensure even coating.
Fermentation: After mixing, allow the Kimchi to ferment at room temperature for at least one day before storing in the refrigerator.