1 Stir in flour a little at a time until smooth, then remove from heat. 2  Add broth and milk a little at a time, stirring to keep mixture smooth. 3  Then, stir in mushrooms. 4  Return to heat and bring sauce to a gentle boil; stir constantly until sauce thickens.
A pound is equal to 16 ounces. If 20 slices equals 1 pound equals 16 ounces, then 1 slice is equal to 16 oz / 20 = .8 ounces. 1 pound = 16 oz = 20 slices. 16/20 oz per slice.
A single slice of American cheese weighs 28 grams. Approximately 7 grams of that slice is fat, 5.5 grams is protein and 2 grams is carbohydrate, the U.S. Department of Agriculture reports. The rest consists of other nutrients and water. According to the USDA, a single slice of American cheese contains 95 calories.