If it looks familiar it’s because it’s almost identical to popovers, though just a tad richer. The main difference with Yorkshire pudding is that — classically — it’s baked in one large pan instead of individual servings (like American popovers). That pan needs to be heated and have at least a few tablespoons of smoking-hot meat drippings in it.
Just as with popovers, a successful Yorkshire pudding depends on well developed gluten, which is why I suggest using a blender, food processor or lots and lots of whisking is you want a decent puff. Assemble:
1 ounce (2 tablespoons) melted, unsalted butter
5 ounces (1 cup) all-purpose flour
3/4 teaspoon salt
2 eggs, room temperature
8 ounces (1 cup) milk, room temperature
1 ounce (2 tablespoons) melted fat from a roast, or lard or butter
Once your roast is finished and resting, crank up the heat in the oven to 450 degrees Fahrenheit. Add a few tablespoons of fat from your roast to a casserole dish, about 9″ x12″. Put all the ingredients in the blender or food processor and blend for about 30 seconds. When the drippings are simmering or even smoking, carefully remove the pan from the oven and pour in the batter. Return the pan to oven and bake for 20 minutes. Lower the heat to 350 and bake another 15 to 20 minutes until the pudding is well browned. Cut into squares and serve.