Combine the oats, salt and flour. Cut in the shortening and add enough water to dampen and form a ball. (A food processor does the work in a jiffy). Leave to swell for ten minutes. Divide the dough and roll each part to 1/8" thickness; slide onto ungreased cookie sheet, indent in squares with a pastry wheel or knife. Bake in 350F for about 1/2 hour but watch that they don't turn brown.
Sweet Oatcake: Add 1 cup sugar to recipe.
Anne's note: That recipe is labelled "Bannock" in the title in cookbook but it far more a non sweet oatcake in the tradition of Walker's oatcakes (it appears as "oatcakes" in the book's index.