A Yorkshire pudding works on the same principle as a French pâte a choux, the thin pastry used to make cream puffs, Parisian-style gnocchi, and gougères. Those recipes all start with a high-moisture dough and rely on the power of steam to puff and rise into their light, crisp final forms. Yorkshire puddings and popovers take the same concept to the extreme, using a batter that is so moist that it pours out like cream and puffs up to at least quadruple its volume.
2 cups all-purpose flour
2 cups milk
1/4 cup vegetable oil
Preheat the oven to 450 degrees F (230 degrees C).
In a large bowl, whisk together the eggs and milk until well blended. Whisk in the flour one cup at a time until frothy and well blended. Set aside.
Distribute the oil equally among 12 muffin cups, a little over a teaspoon per cup. Place in the oven for 5 to 10 minutes, until smoking. Remove from the oven and quickly ladle about 1/4 cup of batter into each cup.
Bake for 30 to 35 minutes in the preheated oven. Serve immediately. I turn my oven off and leave the door partially open with the yorkies inside to keep them from deflating while waiting for everyone to ask for seconds.