Peel the onion, slice into half moon-style slices. Wash and slice the squash into large match sticks.

Heat a skillet. Add a few tablespoons of water or lightly brush the skillet with oil. When the water or oil is hot, saute the onions for 3 to 5 minutes; add the squash and saute for a few minutes, gently stirring the vegetables with chopsticks or wooden spoon. If necessary, add a small amount of water so the vegetables do not burn.

Dilute miso well with a small amount of water and pour over the squash and onions. Cover and simmer 3 to 4 minutes or until squash is tender. Place in serving dish and garnish.