Cut the napa cabbage into four sections and sprinkle salt between the leaves.
Place the cabbage tightly into a large container.
Dissolve the remaining salt in 4 L of cold water and pour over the cabbage.
Place a clean weight on top and leave to salt for 12–24 hours, depending on room temperature.
Rinse the cabbage thoroughly with cold water and squeeze out excess water.
Mix rice flour with 450 ml cold water and cook over low heat, stirring constantly until thickened. Cool completely.
Grate the daikon and mix with 3 tablespoons of gochugaru.
Blend garlic, onion, ginger, Asian pear, and fish sauce until smooth.
Cut green onions into approximately 3-inch pieces.
Combine the daikon, green onions, cooled rice paste, blended mixture, and remaining 5 tablespoons of gochugaru.
Spread the seasoning paste between every cabbage leaf.
Pack the seasoned cabbage tightly into a kimchi container.
Press the kimchi down using the inner lid or a clean suitable weight.
Allow the kimchi to ferment according to your preferred level of sourness, then refrigerate.