The following large recipe is convenient to make, since it freezes well. It takes some preparation, but is pretty easy once you have the stock on hand. Allow time for the onions to cook slowly on low heat, with an occasional stir. They need to be almost overflowing in the pan initially, so use the right size pan. They do shrink down, so stirring them becomes easier.

Before making this soup, have stock on hand. (See Chicken Stock Recipe if necessary). Also, if your family likes roast beef, save the pan drippings, to give your soup more flavor. Makes 3 quarts or so; serves 8-10.

Ingredients:

• 3 lb. sliced yellow onions
• 2 TBS. olive oil
• Approx. 1/4 c. water 
• 2 qt. (8c.)  Chicken or Turkey Stock, plus beef drippings and water as needed, to make 8 c.
• 1/4c. flour
• 1/4c. brown sugar (loose-packed)
• 1 TBS. salt
• 1/4 c. red wine vinegar (or red wine)
• Croutons
• Slices of Swiss Cheese
• Parmesan Cheese
  

 
Saute in 12" iron frying pan: > 3 lb. sliced yellow onions > 2 TBS. olive oil > Approx. 1/4 c. water

Stir often at first, on medium-high heat, until they soften up. Then turn heat down, stirring occasionally, cooking for 1-2 hours until sweet and browned.

Heat in large 4-qt. pot: > 2 qt. (8c.)  Chicken or Turkey Stock, plus beef drippings and water as needed, to make 8 c.

Mix the following well with a fork until smooth: > 1/4c. flour > 1/4c. brown sugar (loose-packed) > 1 TBS. salt
To the flour-sugar-salt mix, stir in: > 1/4 c. red wine vinegar (or red wine)

Bring stock to a boil, add the above mix, and stir well. Boil on medium high for 2 minutes. Add sauteed onions last. Serve hot soup topped with croutons, broiled with Swiss cheese and parmesan on top. Chill any extra soup, putting up into quart or pint containers to freeze.

Beef Drippings-

After roasting a cut of beef of your choice, add 1 c. water to the roasting pan, heating to a boil. Strain the boiled juices, storing up a quantity until you have enough for soup. (Fat will congeal on top after refrigerating, making it easy to remove.)
When it's not convenient to deal with the drippings, just set pan aside in refrigerator for several days, dealing with that project later.
Beef drippings will store in the refrigerator for two weeks, or save up a quantity in the freezer, which will keep several months. Before freezing, let drippings chill completely, so fat can be removed before freezing.