In medium bowl, mix flour and salt thoroughly. Make a well in center.
In another bowl, beat egg, water and oil together. Pour mixture into flour and salt. Mix until well blended; turn out onto lightly floured board and knead for 10 minutes.
Roll out dough into a 20-inch square. Cut butter into slices and arrange in a rectangle in center of dough.
Fold bottom edge up, so only 1/3 of top side of pastry shows. Now fold down the top to 1/3. Fold over sides in same fashion. Roll out with rolling pin to original 20 inch square and fold over as before. Wrap airtight in foil and chill in refrigerator for 20 minutes. Repeat the rolling, folding and 20 minutes chilling procedure 3 times.
On a lightly floured board, roll out the chilled dough as thin as you can. Use a 4-inch diameter biscuit cutter, or tea cup to cut dough in circles. Place 1 heaping teaspoon of cheese or your choice of mixtures in center of each circle.
Moisten edges of circle with cold water. Fold over and seal the edges with a fork. Place each half moon on an ungreased baking sheet. Bake at 400 degrees F for 15 minutes, until lightly browned and pastry puffs up. Serve hot. These may be frozen.
In the 1924 Fannie Farmer Boston Cooking School Cookbook these directions are given for Palm Leaves. (The recipe assumes that you have some leftover puff pastry on hand that you will need to use up. You can, however, use any standard recipe like above for puff pastry.)
Roll remnants of puff pastry one-eighth thick; sprinkle one-half surface with powdered sugar, fold, press edges together, pat and roll out, using sugar for dredging board; repeat three times. After the last rolling, fold four times. The pastry should be in long strip one and one-half inches wide.
From the end, cut pieces one inch wide; place on baking sheet, broad side down, one inch apart, and separate layers of pastry at one end to suggest a leaf. Bake eight minutes in hot oven; these will spread while baking.
hot oven is usually defined as 400 degrees F. This recipe was published in the days before many women had thermostats, or at least very accurate ones, on their ovens.