Put the sliced onions, water and powdered dashi in a pot and bring to a boil.
Lower the heat, cover and cook for 10-12 minutes, until the onions are tender.
Place the miso paste in a small strainer and lower the strainer into the pot, until the liquid covers the miso paste.
Stir the miso paste with chopsticks until it has fully dissolved.
Turn the heat off and serve.
Sprinkle a little ichimi togarashi for heat.
