Miso is one of Japan’s oldest traditional ingredients and was made as early as the 12th century. Today it is produced by combining boiled and crushed soybeans with a culture comprised of wheat and rice, barley, or other beans. The fermented mixture is allowed to mature for up to three years. (See instructions for making it here.)
The three grades available are shiro-miso (white, light in flavor, made with rice), aka-miso (red, medium-flavored, made with barley), and kuro-miso (black, strong flavor, made with more soybeans). The recipe below uses red aka-miso.

• Bring water to boil, add soba (sesame) or other kind of noodles. (I don’t know how much; I don’t measure things unless I have to.) Cook for appropriate amount of time. Turn off heat, drain, toss in a bowl with a little sesame oil, set aside.
• Bring 3c water to boil.
• Grate at least 1 Tbsp ginger, more if desired. Add to water.
• Add a splash of tamari soy sauce. Reduce the heat as low as possible, so that the mixture is not boiling.
• Add maybe 2-3 Tbsp miso paste, then stir occasionally until dissolved. Once the miso has been added, the mixture should not be allowed to reach a boil, as this destroys some of the nutritional properties* and subtlety of flavor. Cook on low heat until the miso paste has dissolved.
• Add a piece or two of kombu (sea vegetable) or some medium-cut strips of nori. Add earlier if using kombu, otherwise toss the nori in at the very end.
• Pour over sesame noodles and serve.

Optional treat for sick people: Add one vegetable bouillon cube early and cook until dissolved. I like Rapunzel brand vegetable bouillon with no salt added, found in the baking section at Whole Foods. This is a good addition to yield a richer broth when desired, but you may prefer to enjoy the flavor of miso without a lot of competition.