Using 1/2 teaspoon shortening for each cup, grease bottom and sides of six 6 oz. custard cups or cups of a popover pan or spray cups with nonstick coating. Place custard cups on 15x10x1-inch baking pan; set aside.
In mixing bowl combine beaten eggs, milk and cooking oil. Add flour and salt. Beat with rotary beater or wire whisk until mixture is smooth. Fill greased cups half full. Bake in 400° oven about 40 minutes or until very firm.
Immediately after removal from oven, prick each popover with fork to let steam escape. Then, if crisper popovers are desired, return popovers to oven 5 to 10 minutes more until desired crispness (be sure oven is turned off). Serve hot.
Whole Wheat Popovers: Prepare as above except reduce all-purpose flour to 3/4 cup and add 1/4 cup whole wheat flour.
Parmesan-Basil Popovers: Prepare as above, except except add 2 tablespoons grated Parmesan cheese and 3/4 teaspoon dried basil, crushed, with the flour.
Onion and Garlic Popovers: Prepare as above, except add 1/4 teaspoon onion powder and 1/4 teaspoon garlic powder with the flour.
Cinnamon Popovers: Prepare as above, except add 1/2 teaspoon ground cinnamon with flour. Serve with honey and margarine or butter, if desired.
These crispy, hollow puffs will be the hit of the meal whether you serve them with an appetizer, salad, or main course.