Combine brown sugar, shortening, and butter in pan and melt over low heat.
Remove from heat; add oatmeal, soda, and salt. Add egg; mix well.
Drop by teaspoons 3 inches apart (they spread a lot!) on cookie sheet topped with parchment paper. Bake at 375 degrees F. for 6 to 7 minutes.
Slide parchment paper from cookie sheet and allow cookies to cool completely before removing from parchment paper. While one batch is cooking, prepare next batch on second piece of parchment paper. Reuse parchment paper for each additional batch of cookies. Makes 4 to 6 dozen of very thin and delicious cookies.
Source: Some cookbook I had more than 20 years ago.
By Dacula from Dacula, GA