Prepare the Cabbage: Start by cutting your napa cabbage into quarters, removing the core, and then cutting the quarters into smaller bite-sized pieces. Rinse and clean the cabbage well to remove any dirt.

Place the cabbage in a large bowl and generously sprinkle coarse salt over it, massaging it well into every piece. Cover with water and place a heavy plate on top to press down. Let the cabbage sit for a while, 1 to 2 hours, until it softens and releases some of its moisture.

Rinse and Drain: Once the cabbage has softened, rinse it thoroughly under cold water to remove the excess salt. Let it drain well, pressing out any excess water.

Make the Kimchi Paste: In a small pot, combine sweet rice flour with water, stirring until smooth. Cook the mixture over medium heat, stirring constantly, until it thickens into a paste. Remove from heat and let it cool.

Prepare the Aromatics: In a blender or food processor, combine a chunk of yellow onion, garlic cloves, and a small piece of ginger. Blend until smooth.

Mix the Kimchi Paste: Once the rice flour paste has cooled, combine it with the blended aromatics, sugar, fish sauce, and gochugaru in a large mixing bowl. Season the paste with a bit of salt, adjusting to taste.

Combine with Cabbage: Add the drained cabbage to the bowl with the kimchi paste along with the green onions and radish. Using your hands (wearing gloves if preferred), massage the paste into the cabbage, ensuring every piece is thoroughly coated.

Pack and Ferment: Once the cabbage is well-coated, pack it tightly into a clean jar or airtight container. Press down to remove any air pockets. Leave some space at the top as the kimchi will expand during fermentation. Seal the jar and leave it at room temperature for a day or two, depending on how tangy you like your kimchi. Then, transfer it to the fridge to slow down the fermentation process.

Enjoy: Your kimchi can be enjoyed right away, but it develops deeper flavors after a few days in the fridge. Serve it as a side dish or add it into any of your favorite dishes.