Miso Soup with Shrimp and Tofu

In a small bowl, whisk 1 cup of the water into the miso. In a medium saucepan, bring the remaining 4 cups of water to a boil with a pinch of salt. Add the edamame, cover and cook until tender, about 5 minutes. Add the spinach in bunches and stir to wilt. Add the shrimp and tofu. Stir the miso mixture and add it to the soup. Simmer just until the shrimp are cooked through, about 1 minute. Season the soup with salt and stir in the sliced scallion. Ladle the soup into deep bowls and serve with steamed rice and toasted sesame seeds.