It’s the raisins and the sherry that do it for this dish.
Cover the unpeeled onions with hot water. Bring to a boil and remove from the heat. When the onions are cool enough to handle, peel, scraping the root ends (do not cut). The skins will slip off easily.
Bring the 1 quart water and salt to a boil and add the peeled onions. Cook until barely tender, about 15 minutes. Drain, reserving the 1-¼ cups onion water.
Heat the butter or margarine, mix in the flour and stir until bubbly. Add the 1-¼ cups onion water and cream. Bring to a boil and simmer for 10 minutes, stirring.
Heat the sherry and add the raisins. Let stand for 5 minutes. Add this to the sauce with the drained onions. Heat but do not boil. Serve with a dusting of paprika.