How to Make It
In a large pot, heat the butter over moderately low heat. Add the onion and garlic and cook, stirring occasionally, until translucent, about 5 minutes.
Add the pumpkin, stock, salt and dried sage, if using. Bring to a boil. Reduce the heat and simmer, covered, until the pumpkin is tender, about 30 minutes. Stir in 1 tablespoon of the fresh sage, if using, and simmer 5 minutes longer.
Puree the soup in a blender or food processor until smooth. Strain the puree back into the pot and add the cream. Stir in the pepper. Simmer over low heat for 5 minutes. Top with the remaining 1 tablespoon chopped fresh sage, if using, and croutons, if you like.