Prepare the cabbage: Cut the Napa cabbage into halves and then into 1-inch segments. Layer the cabbage with salt, using at least 1/4 cup, making sure to work the salt between the layers.
Cure the cabbage: Let the salted cabbage cure for about 1 hour until it releases water.
Rinse the cabbage: Rinse the cabbage thoroughly to remove all salt. Make sure no salt remains to avoid overly salty kimchi.
Prepare the kimchi paste: Blend Korean pear, garlic, ginger, and fish sauce until smooth. Add Korean chili flakes and mix well to form a spicy paste.
Mix vegetables and paste: Drain the cabbage well. Add carrots, spring onions, and daikon radish. Mix all with the kimchi paste thoroughly, preferably wearing gloves to protect sensitive skin.
Pack and ferment: Pack the mixture tightly into a glass jar, pressing down to remove air bubbles. Keep in a cool, dark place to ferment for about 6 days (150 hours). Burp the jar daily to release gases and press down to remove air bubbles.
Store: After fermentation, seal the jar and store in the refrigerator for up to 2 to 3 months.