Cut a chayote in half lengthwise and remove the inner seed. Slice each half into ½ inch thick pieces lengthwise and then cut each piece crosswise into roughly ½ inch cubes. Transfer the cubes to a large bowl. Repeat with the rest of chayotes.
Add 2 tablespoons kosher salt and mix well. Let sit for 30 minutes, turning it over every 10 minutes to salt evenly.
Pour out the excess brine to a blender. Add garlic, ginger, onion, and fish sauce (or soy sauce). Blend 1 minute until soft and creamy.
Add the mixture to the chayote chunks. Add gochugaru (Korean hot pepper flakes), green onion, and mix all together by hand. You can wear a disposable glove if desired.
Transfer it to a jar or an airtight container. Press down the top of the kimchi and cover.
You can serve it right away with rice. If you like to ferment your kimchi faster, you can keep it outside the fridge. Usually it will take a few days to ferment at room temperature, but if you live in a warm country it may only take 1 day because of the higher temperatures. When the kimchi is fermented, it tastes sour. Be sure to store it in the fridge and enjoy it until it runs out.
