The recipe yield is:
In a saucepan over moderately low heat, melt butter and stir in the onions. Cover and cook slowly until the onions are transparent. Blend in the flour. Stir slowly for 3 minutes, to cook the flour without letting it color. Remove from heat and, when bubbling stops, pour in 1 cup of hot liquid all a once, whisking vigorously to blend smoothly. Whisk in 6 more cups. Bring to a simmer, stirring, and simmer for 10 minutes, stirring frequently. The soup base should coat a spoon lightly; add dollops of more liquid if too thick. Correct seasoning, and continue as your recipes directs. Makes about 2 quarts. Suggestion: Use with Upperline's Ancho Crab Soup or Flagon's Cream of Mushroom and Brie Soup. Recipe from Julia Child's "The Way to Cook", New Orleans Times-Picayune, November 7, 1991.