Cut 1 large napa cabbage in half lengthwise. Then cut each half into quarters. Wash each piece throughly and place into a sieve with a large bowl underneath.
Add mix coarse sea salt with water and pour evenly over cabbage. Let sit for 2 hours.
After 2 hours, rinse the cabbage several times under cold water. Let cabbage drain.
In a separate bowl, make the spice paste. Mix hot pepper flakes, fish sauce, sugar, minced garlic, scallions, and a handful of julienned daikon. Mix well until it forms a thick paste.
Put on a pair of gloves and use your hands to toss the brined cabbage in the paste. Ensure that each piece is evenly and well coated.
Store in sealed jar. Eat fresh or keep refrigerated.