I never measure anything when I make miso soup, but it always turns out great!
Into a saucepan, crumble up about a half a stick of dried kombu. Throw in 3 dried shiitake mushrooms and cover with boiling water--about 3 or 4 cups. Put the lid on the pot and go and do something for half an hour. You're just letting the kombu and mushrooms soften in the hot water, no heat under the pot.
Come back and take the mushrooms out of the water, remove the stems and discard. Slice the mushrooms thin. Return them to the pot and turn on the heat to medium. Add a packet of dashi powder and a tablespoon or two of mirin. When the stock is very hot, stir in two fat tablespoons of red miso and stir. Turn off the heat and put the lid back on the pot. Push to the back of the stove and go ahead and make your other dishes.
Tonight we had brown rice and barley mixed with courgette, carrot and onion (stir fry), accompanied by bowls of miso soup. You could put strips of pan-fried tofu over the rice in the bowl, but we had veggie sausages for lunch and didn't need any tofu. If you wanted to make it a complete Japanese meal, add a tiny dish of pickled vegetables, a couple of side vegetables and a cup of green tea.