Evaporated milk, processed cheese and Worcestershire sauce.
This is the second of two recipes for cheese sauce in this box. The other is here.
From a box sold in San Antonio, Texas.
Place 1 small can evaporated milk and 1/4 tsp. salt in saucepan. Heat to simmering, about 2 to 3 minutes. Add 1 cup grated process-type cheese and 1/4 tsp. Worcestershire sauce. Heat, stirring constantly until thickened and smooth. Makes 1-1/2 cups sauce.