Wash the cabbage leaves and let them soak overnight in a brine of 1 cup sea salt and 1 gallon water.
Once soaked, discard the soaking liquid and combine the cabbage with the radishes, carrots, scallions, ginger, garlic, fish sauce and chili paste.
Add the remaining 1/4 cup sea salt to the mixture and combine well.
Place the mixture little by little in your fermentation jar, pounding it vigorously to release the juices.
Make sure that the extracted water covers it entirely. If not, create a brine of 2 tablespoons sea salt to 4 cups water and add it to the mixture.
Press the mixture and keep it under the brine by placing a plate or a lid on top weighted down by a rock or a jug of water. Cover with a clean towel if needed to keep out fruit flies.
Place the fermentation jar in a warm spot in your kitchen and allow the kimchi to ferment for 5 to 7 days.
Check on it from time to time to be sure that the brine covers the mixture and to remove any mold that may form on the surface.
A good way to know when it’s ready is to taste it during the fermentation process. It’s ready when you’re satisfied with the taste.