Source: "So This Is Kosher" by Ann Kaye and Hetty Rance, 1986
Melt the margarine in a medium saucepan, and cook the parsnips and apples, tossing well until coated. Cover and cook gently over low heat 10-15 minutes, stirring occasionally, until the apple juices start to run. Pour in the stock and add the sage, parsley, salt and pepper. Bring to the boil, then simmer gently 30-40 minutes or until parsnips are soft.
Pass through a food mill or puree in a blender or food processor until smooth. Return to pan and reheat gently. Add a little hot soup to the egg yolks, stirring well, then add the eggs to the soup. Do not allow to boil
Serve with matzo and butter as a light meal.