Preheat the oven to 350 degrees F.
Cut the squashes in half lengthwise. Scoop out the seeds and discard. Place 1/2 tablespoon of butter in each squash and place the squash halves on a cookie sheet. Bake for about an hour or until the insides of the squashes are fork tender.
Heat the olive oil and the red pepper in a five-quart saucepan over medium high heat. Sauté the peppers in the oil for about one minute. Add the garlic, onion, and ginger. Continue stirring and cooking for about three minutes. Add the potatoes and continue cooking, stirring frequently, for about five minutes. Stir until the potatoes start to soften. Add the hot broth and reduce the heat to medium low.
Scoop out the insides of the cooked squashes into a large mixing bowl. Mash lightly before adding to the contents of the pot. Simmer for about 15 minutes, stirring occasionally.
Remove the soup to a food processor in batches, adding some whole milk to each batch. Return the puree to the soup pot. ( or use a submersible blender and blend til smooth).
Place the miso in a small bowl and add the sherry to it. Blend with a fork or small whisk, then add to the soup. Add the garlic and the nutmeg. Simmer gently for about ten minutes, but take care not to boil. Additional chicken broth may be added if it's too thick for your taste.
Place the piping hot soup into individual bowls and sprinkle lightly with nutmeg.