Sweet potato growers know that harvesting the crop is not the final step from garden to table. To increase the sugar content, sweet potatoes require several days of curing in a warm, humid environment. After curing, the potatoes can be stored, in boxes or bins, in a cool, humid area for up to 10 months. Keep a few of them on hand in the kitchen, though, because sweet potatoes are a nutritious addition to a creamy winter soup.
Melt the butter in a large stockpot, set over medium heat.
Add the sweet potatoes, onion and garlic and saute until the onions just start to brown.
Add the broth to the pot and bring the mixture to a boil. Turn the heat to low and simmer 25 minutes, or until the sweet potatoes are soft.
Combine the pumpkin, nutmeg, ginger and salt, to taste, in a medium bowl. Add the mixture to the pot and stir well. Remove the pot from the heat and allow it to cool for 5 minutes.
Puree the mixture, in batches, in a blender or food processor until it is smooth. Stir in the cream and return the pot to the stove. Heat the soup on low until it is warmed through and serve immediately. Add more broth if the soup is too thick. Makes six 1-cup servings.