Preheat the oven to 425°F. Combine flour and salt in a bowl and whisk the eggs and egg white into the flour well.
Add 10 ounces of milk and whisk well. This will result in a thick batter. Lift a spoon in and out to check the consistency. If the batter is too thick, whisk it in a little more milk.
Place in the refrigerator for 24 hours. After taking it out of the fridge, let it rest for at least 30 minutes.
With this quantity of batter, you can fill ten to twelve individual tins (4-inch) or two 12-hole pudding moulds.
Make sure your chosen tins are greased generously with oil and melted fat. Heat them in the oven until almost smoking. Fill each almost to the top with the batter when the pans are hot.
Bake in the preheated oven for about 25 to 30 minutes, or until it is golden and risen. Remove from the oven and serve!