Instructions

Beat the eggs and egg white in a measuring cup or small bowl; you should have ½ cup (discard the excess). Set aside.
Bring the butter, milk, water, sugar, and salt to a boil in a small saucepan over medium heat, stirring once or twice. When the mixture reaches a full boil (the butter should be fully melted), immediately remove the saucepan from the heat and stir in the flour with a heatproof spatula or wooden spoon until combined and the mixture clears the sides of the pan. Return the saucepan to low heat and cook, stirring constantly, using a smearing motion, until the mixture is slightly shiny, looks like wet sand, and tiny beads of fat appear on the bottom of the saucepan, about 3 minutes (the paste should register 175 to 180 degrees on an instant-read thermometer).
Immediately transfer the mixture to a food processor and process with the feed tube open for 10 seconds to cool slightly. With the machine ­running, gradually add the eggs in a steady stream. When all the eggs have been added, scrape down the sides of the bowl, then process for 30 seconds until a smooth, thick, sticky paste forms. (If not using immediately in one of the following recipes, transfer the paste to a medium bowl, press a sheet of plastic wrap that has been sprayed lightly with nonstick cooking spray directly on the surface, and store at room temperature for up to 2 hours.)