Bring 2 quarts of water to a boil in a 4-quart saucepan
. Add the fried tofu
and simmer for 10 minutes. Add the squash and simmer
for another 15 minutes. Add the remaining ingredients, except for the miso
and scallions, reduce the heat to low and simmer, covered, for about 10 minutes. Remove from heat.
In a small bowl, whisk together the miso and 1/2 cup water until the mixture is smooth and thinned out, then add the miso to the pot. Stir well and serve immediately, garnished with the scallions.