In traditional Japanese cuisine, miso soup is served for breakfast every day, and often served with meals as well.
Variant One 
- 1/2 tsp. of sesame oil
- 3 cups of water
- 2 tbl. of miso
- 2 green onions, finely minced (optional)
- 1/2 cake tofu, cut into 1/2 inch cubes (optional)
- 2-3 fresh mushrooms, thinly sliced (optional)
- 5-6 shrimps, cubed or shredded (optional)
- Some pieces of seaweed (optional)
- Heat oil in the bottom of a small pot
- Add green onion (if using)
- Cook for a few minutes while stirring frequently
- Add 2 1/2 cups of water
- Bring to a boil
- Dissolve miso in 1/2 cup of water and add to pot
- Lower heat and add mushrooms, seaweed & tofu if desired
Variant Two 
- 90% to 94% dashi (consider using instant dashi mix)
- 6% to 10% miso. It can be aka(red) or shiro(white), or a combination.
- odds and ends for garnish
The garnish would typically be two to three items that contrast in color, flavor, buoyancy, shape, texture, etc. Wakame with tofu is a standard and popular combination, especially at restaurants. Some common items for garnish are:
- finely sliced and deep-fat fried tofu (Agedashi tofu)
- finely cubed raw (silky) tofu (recommended)
- wakame seaweed (recommended)
- konbu (kelp) seaweed, perhaps left over from making dashi
- chopped scallion (recommended)
- grated daikon radish
- boiled and finely cubed potato
- clams (asari or shijimi)
- grated eggplant
- Put dashi in a pot.
- Add any garnish that needs cooking.
- Heat the dashi, letting it simmer, cooking any garnish that needs cooking. Do not bring to a rolling boil, as this degrades the flavor.
- Add any garnish that does not need cooking, and remove from heat.
- Add the miso to the soup. Avoid boiling the miso; some nuances of the flavor will be lost.
Modern Variant 
While certainly a traditional food, miso is also suited to modern interpretations. One non-traditional yet delicious way to make miso soup is as follows:
- Heat frying oil in a small pot
- Fry onions and cabbage in the oil over high heat until browned. A slight degree of burning is acceptable.
- Proceed with the traditional method listed above.
Using oil leftover from frying bacon and caramelizing the sugars in the onion and cabbage through high heat, this method produces a soup notably different from the traditional variety, and can add new interest to a classic dish. A small quantity of freshly ground black pepper added just before serving rounds out this method very well.