Slice the Napa cabbage into quarters, remove the core, chop into bite-sized pieces, rinse under cold water, and drain.

In a bowl, rub kosher salt over cabbage pieces. Submerge in water with a weight for 1.5 hours.

Combine glutinous rice flour with 1 cup of water in a saucepan, cook over medium-low heat until thickened, then cool.

Mix cooled porridge with garlic, ginger, red onion, green onion, fish sauce, sugar, and hot pepper in a large bowl.

Add drained cabbage to the kimchi paste, mix well to ensure even coating.

Transfer to an airtight container, press down to remove air pockets, and store at room temperature for 2 days before refrigerating.