In a bowl combine shortening, butter, brown sugar, granulated sugar, and peanut butter until smooth.
Beat in eggs one at a time.
Combine flour, soda, and salt and stir into creamed mixture.
Mix in oats until just combined.
Refrigerate dough for 15 minutes.
Using a quick-release scoop, drop onto an ungreased cookie sheet. I like to line mine with a silicone mat.
Bake 9 to 12 minutes or until just lightly browned. Cook time will vary depending on how big your cookies are. I used 2 tablespoons of dough and baked for 9 minutes. I prefer soft, chewy cookies. Bake longer if you like crisp cookies.