This is a traditional style of Korean kimchi, made with green onions. It really doesn't matter what kind you use: Scallions, green onions, ramps, or in my case, Allium triquetrum, the three-cornered leek. This is a fermented pickle, with no vinegar, so you need to follow the instructions closely when it comes to salt, or in this case fish sauce. You can use soy sauce in place of fish sauce, but it won't be the same. The salt level kills most spoilage bacteria while letting the good bacteria thrive. You literally want to see a little bit of fizzy action going on with this kimchi when it's ready.
Make sure all the green onions are clean. If the tops have not been trimmed, cut off about 1 to 2 inches of the top green part, which is very stringy. Dissolve the kosher salt into 5 cups of water. Soak the green onions in the water for 1 hour.
Meanwhile, bring the other cup of water to a boil and whisk in the rice flour. Turn off the heat and keep stirring until the flour is totally incorporated into the water. Let this cool while the onions soak.
When the rice flour mixture is cool, mix in the remaining ingredients and put everything in a very large bowl or a rimmed baking sheet.
Take each onion and, if you want, wrap the green end around the white part to make each onion more compact; most Korean recipes do this. Alternatively, you can chop them coarsely.
Put on some latex or rubber gloves if you have them, because you're gonna get messy. Mix the onions with the spice mixture so they are completely coated, then cram them into quart Mason jars. Leave about 3 to 4 inches headspace. You can take your gloves off now. Find a smaller jar or some sort of clean weight -- I used narrow jelly jars -- and fill it with water. Use this smaller jar to weigh down the kimchi in the Mason jar so it is totally submerged. Let these jars sit in a cool, dark place (cool room temperature is perfect) for at least 3 days, and up to 2 weeks.
To store, remove the smaller jars and redistribute the kimchi into wide-mouth pint jars. Cap and refrigerate for up to 6 months.
Storing it in the fridge radically slows the fermentation, and once made this kimchi will keep for months. Just be sure to eat some every few weeks -- or at least open the lid. Pressure will slowly build up in the jar, and you will need to relieve that. Serve the kimchi alongside mild meats such as fish or chicken, or as a condiment with rice or other foods. It's also good minced and stuck inside a dumpling.