Quarter the cabbage and core
Cut each quarter into 2" by 1" pieces
In a large bowl, combine the cabbage with the salt.
Mix thoroughly with your hands so the salt is well distributed.
Set aside for about 50 minutes. Lightly rinse the cabbage to remove any traces of salt and drain in a colander for 10-15 minutes.
In the meantime, mix garlic, ginger, fish sauce, and sugar until a paste forms.
Mix in the chile peppers and let the paste combine for 15 minutes so the flavors meld.
In a large bowl, mix the green onions, yellow onion, the seasoning paste, and the drained cabbage.
Add the seasoning paste and mix until it's thoroughly incorporated.
Pack tightly into a quart glass jar pressing down to make sure it's firmly packed. Add 1/4 cup water into the mixing bowl and swirl to get all the remaining seasoning paste and pour into the jar.
Set aside for 3 days at room temperature. The cabbage will expand as it ferments so be sure to place the jar on a plate.
After 3 days, the kimchi is ready to consume! Refrigerate whatever remains and enjoy for up to 6 months. You'll notice the the flavora and texture will take on complexity as it evolves.