15 lbs chipped beef soaked in water for 24 hours in refrigerator which will soak out a lot of the salt in meat
1 lb butter
1-¼ lbs flour 
2 cans (12 oz each) evaporated milk 
1 bunch chopped parsley leaves 
¼ oz black pepper 
6 quarts canned beef broth
1/4 cup worcestershire sauce
50 slices toast

In a large enough kettle: melt the butter, add the flour and lightly brown the flour. 
Mix the milk with the Worcestershire and the beef broth and then add that to the pot. Stir this together slowly to prevent lumping and bring to a slow boil (thin with tap water as needed), after it thickens turn off the heat, add and stir in the pepper and only the dried beef (throw away the water used for soaking) Cover pot and let set for 10-15 minutes, add and stir in the chopped parsley. 

You could pour it in large baking pans and keep it warm in a 200-F oven until ready to spoon it over dry cold toast.

Serves 50-60