Chop the cabbage roughly. Put into a large airtight zip bag or a plastic bag.
Add the shio-koji and close the bag firmly. Shake so that the shio-koji is distributed evenly.
When done, chill in the vegetable compartment of the fridge (put a weight on top to pickle faster).
It'll become saltier as it pickles, so salty it slightly on the first day.
Sprinkle sesame oil to serve. (It's tasty even when freshly made!)
Here's how it looks on the following day. The cabbage produces some excess liquid, so make sure to shake the bag occasionally so it pickles evenly.
Here's a photo from the second day.
I usually make tons to eat throughout the week, but it's so tasty that it usually doesn't last that long!
You can also serve it without pickling, then it tastes like a salad.
Here's a recipe for shio-koji: All-Purpose Flavoring, How to Make Shio Koji Salted Rice Malt (For Storing) - Recipe ID: 2051544.
Story Behind this Recipe
Because cabbage is so nutritious, I pickle it with shio-koji to eat everyday. One time I drizzled sesame oil and it really improved the taste. Ever since then I've served this dish with sesame oil.
When putting the cabbage into a bag, add half of the shio-koji part way through. When all the cabbage is in the bag, add the rest of the shio-koji. This makes it easier to distribute. Please adjust the amount of shio-koji since the salt content varies by brand. If you use a zip lock bag, it lasts longer.