a mix of egg yolk with water or milk and brushed over bread or pie before baking to enrich the color and gloss
Some recipes will have you brush with egg wash the surface of a pastry shell being baked "blind," in order to seal the surface against moisture from the anticipated filling.
Brush the pastry with egg wash and sprinkle with fleur de sel and pepper.
Place a pastry circle over each bowl, adhering it with the egg wash.
Coat each stuffing bite with this egg wash, then dredge in the bread crumbs until fully coated and set aside.
Note: The egg wash both affixes the pastry to the dish and makes a lovely browned crust.