Yorkshire pudding is the classic English accompaniment to roast beef: a batter of eggs, flour, milk, and salt, poured into smoking-hot beef dripping or oil and baked in a fierce oven until it puffs into a tall, crisp, golden shell. The extreme heat makes the batter’s water flash to steam, ballooning it dramatically — a triumph of physics as much as cooking. Traditionally served as a first course with gravy to fill hungry diners cheaply, it now usually accompanies the roast itself, and giant versions hold entire Sunday dinners. The batter must rest, the fat must be smoking, and the oven door must stay shut. Few dishes reward technique so visibly.