In large glass measuring cup, whisk flour and salt. Add eggs and milk; whisk until smooth and well blended. Cover and refrigerate for at least 30 minutes.
Preheat oven to 425°F (220°C). Spoon ½ tsp (2 mL) of oil into each cup of a muffin pan. Place pan in oven, on upper third shelf, until very hot and almost smoking, about 13 minutes.
Remove pan from oven and pour batter into muffin cups to about ½ full (it should sizzle) and immediately return to oven. Bake for 20 to 25 minutes or until golden brown and crisp (do not open oven door during baking). Transfer to cooling rack and remove puddings from tray. Serve warm.
Yorkshire Puddings are also great served as an appetizer or light meal filled with horseradish cream (plain yogurt, prepared horseradish and chopped fresh chives) and smoked salmon or thinly sliced roast beef. These can be made ahead, cooled and frozen in air-tight containers. You can replace vegetable oil with meat drippings when cooking roast beef.
My mothers parents were British and while this recipe is very similar the directions are off. My mother would tell me the importance it was to beating the eggs before adding any other ingredients. Milk would be added next with another significant mixing. Then slowly the flour & salt blended until smooth. You should also always sift the flour before measuring. This helps to keep the Yorkshires light. Mom use to bake these when having a Sunday night roast beef dinner and she never ever used oil in the pan but drippings from the roast. This helps boost the flavour. My grandchildren call them eggy puddings. You can also pour the mixture into a pan then cut into pieces.