Slice meat into flimsy slices about 1 inch square and 1/16 inch thick.
Mix thoroughly the slices with the soy sauce, sherry, cornstarch, sugar, and water.
Wash and slice mushrooms.
Heat 2 tbsp. lard or oil in a skillet till hot.
Put in mushrooms, and keep stirring for 2 min. Then take out mushrooms and put in a dish or bowl.
Use another tbsp. of lard or oil and put the flavored meat in the pan and stir constantly to keep meat from burning.
After meat is cooked for 2 min., add in the mushrooms again and cook together for 30 seconds.
Add salt if desired.
