Patty Shells:

Mix the flour and salt in a large bowl. Cut in the shortening with a knife, then use your hands or a pastry blender to rub the shortening into the flour until the mixture is crumbly.
In a measuring cup, beat the egg. Add the vinegar and enough water to make 1 cup. Stir. Make a well in the center of the flour mixture and add 1/2 cup of the egg mixture. Stir with a fork until the mixture forms a dough, adding more liquid a tablespoon at a time if necessary. Roll the dough into a ball, flatten it into a disk, wrap it in a clean kitchen cloth, and refrigerate it for 1 hour.
Divide the dough into 15 to 20 equal portions, and roll each portion into a ball. On a floured surface roll each ball to the size of a salad plate (about 6 inches in diameter). Fill and bake according to your recipe.

Vegetable Filling:

Fill patty shells with your favorite cooked vegetable, most people prefer cabbage and carrots in their veggie patties.

Enjoy!