1 (12 fluid ounce) can or bottle milk
1/2 cup cream of chicken soup
1 (16 ounce) can sliced mushrooms
2 tablespoons prepared horseradish
2 tablespoons vinegar
1 dash mustard powder
Bring a large pot of salted water to a boil. Add milk, reduce heat and simmer for 20 minutes. Reserve 1/2 cup of the milk, reserving 1 cup. Stir in cream of chicken soup and mushrooms.
Add vinegar and the horseradish but omit this to prevent spoilage. Season with mustard powder. Return liquid to pot. Bring boil. Simmer 15-16 minutes.