Tsukemono (say "TSKEH-mohnoh" never "TSOOkeh-mohnoh"... just think of the "su" part as being whispered instead of spoken) means "pickled things" and includes a great variety of Japanese pickle, both fruit and vegetable types. This Instructable is about one of the most basic, called "Hakusai no Shiozuke" or "Napa Cabbage Salt Pickle".
Once you feel comfortable doing this, you can try endless variations, with seaweed, scallions, peppers, garlic, fish sauce or broth... in many ways, depending on how you dress it up, this can be very similar to Korean Kimchi.
There is no vinegar added.. like all naturally fermented pickles, the varying sourness is from natural vinegar that gets made as part of the fermentation process, so while you can simply put salt and vinegar on cabbage, not only would that be "cheating" but it would cheat you of the full flavor and priobiotic benefits to the gut and immune system, that naturally fermented original versions offer.
Once you see how simple this is, you can have it all the time, and it is good with rice, alone as a snack, added to soup after the soup is done, on sandwiches like sauerkraut, or however you like it.
This is quick to make and must also be used more quickly, than slower fermented things like kimchi. But it's easy enough that there is no need to make more than you can use in a short time.
Step 1: Tools and Materials
All you need is Napa cabbage, salt, and a knife.
Oh, and a makeshift "tsukemonoki" if, like most of us, you don't have access to a traditional Japanese pickling crock. Use any container that is big enough, and lets you weight the top down. I used a 2-quart square food-safe plastic freezer storage container, with a 1-quart one full of water as the weight. You could use a large nonreactive bowl with a plate on top weighted by a brick. Or if you have a tsukemonoki, tell me where I can get one too.