Bring the egg to room temperature by letting it sit out for about 10 minutes before starting.

Crack the egg into a small mixing bowl, ensuring no shell fragments remain.

Add 1 tablespoon of water, milk, or cream to the bowl, depending on the desired richness and browning level.

Sprinkle in a pinch of salt if using, and let the mixture stand for 30 seconds so the salt can begin breaking down the egg proteins.

Beat the mixture vigorously with a fork or small whisk for about 30 seconds, until the liquid is uniformly yellow with no visible streaks.

For an ultra-smooth wash, pour the mixture through a fine-mesh strainer into a clean bowl, discarding any stringy bits that remain in the strainer.

Dip a pastry brush lightly into the egg wash, tap off excess, and brush thin, even strokes across the surface of your unbaked pastry, working in one direction to avoid pooling.

If a deeper color or shine is desired, allow the first coat to dry for 3–5 minutes, then brush on a second thin layer just before the pastry goes into the oven.