It is served to invalids, and at New Year.
You cut vegetables in large chunks. You don’t mix the pieces of vegetable; you put each in its own area at the bottom of the pot. You then add water. You use just a bare sprinkle of water, just enough to barely cover the bottom of the pan, less than 1/4 inch (use about 1/8 inch or 3 to 4 mm), and cook slowly for about 30 minutes. Then, season with a few sprinkles of soy sauce, mirin, miso, and tamari, and cook another 3 to 5 minutes. After cooking, you can mix the vegetables if you want, or serve them separately.
You use root vegetables, particularly starchy ones. Vegetables might include onion, carrots, daikon radish, turnips, Yamagoboo (burdock), lotus root, squash, cabbage, kombu (seaweed.) Occasionally, some small pieces of pork might be added. You can also use Yaki Dofu (lightly-grilled tofu which will hold its shape well), or dried tofu. Tofu is used particularly in the Kanto region of Japan. Soy sauce is used to flavour the tofu.
Tough pot herbs can be used, but not more tender ones.
The vegetables sweeten during the long cooking time as the starches convert to sugar. The cooking time is considered “long” by Japanese standards, though not by Western.
The minimal amount of water used makes it sort of like “sweat” cooking or “dry-braising.”
You need a thick pot that holds and distributes heat well, such as clay or cast iron.