Quarter the cabbage. Chop into one inch pieces then place into a large bowl. Sprinkle 1/2 cup of salt onto cabbage and massage so the salt is mixed throughout the bowl. Top with cold water and let the brine rest overnight.
The following day strain the cabbage and rinse with cold water.
Add daikon, gala apples and green onions to cabbage bowl.
Blend fish sauce, ginger, garlic, gochugaru and red pepper flakes. Pour into cabbage bowl and with a large spoon mix the contents until fully incorporated.
Scoop kimchi into latch jars and use the back of your spoon (or a measuring cup) to push the cabbage into the jar so it is compact. Ensure that the brine covers the kimchi otherwise the top will go bad and mouldy. In order to weigh down your kimchi you can use sterilized weights, extra cabbage leaves, or fermentation rocks.
For the first 3-5 days store your kimchi bottles at room temperature. Each morning open up each jar to ensure the build up of gas escapes (you don't want an explosion of glass on your hands).
Kimchi is typically properly fermented and ready to enjoy 5-7 days. After fermentation is complete store in your fridge.
Sprinkle with roasted sesame seeds and enjoy with rice, noodles and grilled meats.