Beat flour, salt, eggs and milk together until very smooth, scraping bowl occasionally.

Refrigerate 2 hours or longer.

Heat oven to 450°F (250°C). Measure oil into 8x8x2-inch OR 20x20x5cm square pan. Heat for 2 minutes. Pour batter in pan and bake for 20 to 30 minutes. Do not open door. Serve immediately.

Note: When fresh from oven, good Yorkshire pudding is a puffy irregular-shaped golden mass, unlike any other baked dish. On standing a few minutes, the surface settles more or less evenly and when cut, the outer crust is tender and crisp while the center is soft and custard-like.