Heat oven to 350 degrees F. Lightly butter 1 1/2-quart casserole. In medium saucepan, heat water, margarine and salt to rolling boil. Remove from heat. Stir in milk and potato flakes. Blend in egg, sour cream and cheese, mixing thoroughly. Scoop or spoon into prepared casserole. Bake at 350 degrees F. for 20-30 minutes, until lightly golden brown and puffed. Refrigerate leftovers.
I have not tried this recipe yet. It comes from my "PIllsbury Festive Holiday Recipes" cookbook, Classic No. 13. Marilyn Sultar