Cream of Spinach Soup
Add the spinach to the saucepan, reduce the heat to low, and cook, stirring with a fork, until just wilted if using fresh or until well separated if using frozen. Sprinkle the spinach with the 3 tablespoons flour and stir once. Add the 5 cups hot chicken broth, stirring constantly, and bring the mixture to a boil over high heat.
Carefully pour the mixture into a blender or food processor and puree it.
Return the soup to the saucepan and add the 1/4 teaspoon salt and pinch of pepper.
Keep the soup warm In a small bowl, stir together with a fork the 2 egg yolks and 1/2 cup cream. Add a little of the hot soup to the eggs and cream, stir to combine, then stir this mixture into the hot soup, whisking rapidly.
Heat thoroughly but do not boil. Add a little nutmeg and stir in the remaining 1 tablespoon butter.