Here is my family's recipe for Yorkshire Puddings. Since I am a first-generation American (my mum and her family all come from London, and she still lives there) you can rest assured this recipe has been made in the "Old Country" for many, many years.
Very simple and virtually foolproof...and very delicious!
Gannon's Yorkshire Puddings
1 cup milk
4 heaping tablespoons all-purpose flour
pinch of salt
1. Preheat oven to 450.
2. Mix flour and salt together in a bowl
2. Mix milk and egg together in another bowl.
3. Add the egg/milk liquid to the flour mix, adding a little at a time, stirring until it has a batter-like consistency.
4. In a muffin tin, add a small pat (probably 1/2 teaspoon, no more) of bacon fat, butter, or oil of your choice to the bottom of each tin, and place tin in the oven.
5. Once the oil is hot, but not smoking, remove from oven and add some batter to each tin. Should be no more than halfway full, as it will rise when it cooks.
5. Cook for about 20 minutes.
6. Remove and enjoy!