Combine eggs, flour, milk, water, salt, and whisk until smooth.
Let batter rest at least 30 minutes at room temperature (see below).
Oven rack in the middle, preheat to 450F
Divide the oil/fat/etc. between the cooking containers (see below).
Preheat the cooking container until the oil is smoking hot, approx 10 minutes.
Fill the wells 1/2 - 3/4 (1/4 for pan), and immediately return to oven.
Bake until quadrupled in volume, deep brown all over. 15 min for smaller ones, 20-25 for larger ones. DO NOT OPEN THE OVEN DOOR.
Serve immediately.