To prepare a classic creamy carrot soup, melt 1/4 cup of butter in a Dutch oven. Add 1 cup of chopped onion and sauté it until it becomes tender. Peel and cube a potato and add it to the onions, along with 4 1/2 cups of sliced fresh carrots.
Pour in two 14 1/2-ounce cans of chicken broth and 1 teaspoon of ground ginger. Cover the mixture and cook it for 30 minutes over medium heat until the vegetables are tender. Remove the Dutch oven from the heat and cool the soup for 15 minutes.
Transfer the soup mixture to a blender, in batches if necessary, and purée it until it is smooth. Return each batch to the Dutch oven. Once the entire mixture has been puréed, stir in 2 cups of heavy whipping cream and 1 teaspoon of chopped dried rosemary. Cook the purée over low heat for a few minutes, then serve. This recipe makes 2 1/2 quarts of soup.
To make a lighter version of this carrot soup, substitute the heavy whipping cream with about 1 cup of half-and-half and 1/2 cup of 1 percent milk, adjusting the liquid to reach the desired consistency. To increase the ginger flavor, increase the amount of dried ginger to 3 1/2 teaspoons or used freshly grated ginger to taste.