This is the famous "Chicken Velvet Soup" recipe from Thousand Pines Conference Center in Crestline, California. It is a winner every time, and also works well with broccoli (or other ingredients) instead of chicken.
Submitted by Diane Boone

Ingredients:
2 1/2 lb. (1.1kg) Margarine
2 lb. (900g) All Purpose Flour
1 1/2 tsp. (7ml) Pepper
1 Tbsp. (15ml) Poultry Seasoning
2 1/2 gal (9.5l) Chicken Stock (or water with chicken base)
6 1/2 qt. (6l) Milk
5 lb. (2.3kg) Chicken, cooked and diced

Procedure:
Melt margarine in saucepan; add flour, pepper and poultry seasoning. Mix and cook roux for 4-5 minutes. Combine chicken stock and milk in stockpot and heat until hot (185'F/85'C). Add roux slowly. Cook over low heat until thickened and smooth, stirring frequently. Add chicken. Allow to stand and develop flavor. Adjust seasoning if necessary.