Simple and quick: Heat up water, or chicken broth, or dashi in a pan on the stove. Optional: Drop in a few thinly sliced carrot, parsnip, turnip or celery pieces and simmer a few minutes until almost tender. Optional: add smallish tofu cubes or precooked shredded meats such as chicken. Continue to simmer gently until everything is hot. Remove from the heat and stir in miso to taste. Ladle into a bowl. Optional: a few parsley or cilantro leaves, thinly sliced green onion or spinach leaves. Or crack a good farm egg into the bowl of soup, cover and let sit for a few minutes. The hot broth will poach the egg.
Use yellow miso for a mild flavor or red miso for a stronger, deeper flavor.
Good nutrition: Miso is loaded with good vitamins and minerals, including magnesium and vitamin K. It is also high in essential amino acids.
Nourishing: Miso does contain some tryptophan which can cause drowsiness in some people, although I've never noticed this. Tryptophan is also a mood elevator and is considered good for depression and anxiety as well as digestion. Most importantly, pausing for a few minutes to sip your miso soup before rushing out into the day is a nourishing act. You may think you don't have time for it but you do!
Related: DIY Recipe: Miso Soup