1 whole egg, room temperature
1 tablespoon freshly-squeezed lemon juice, plus more if needed
1 teaspoon Dijon-style mustard
1/2 teaspoon salt
¼ teaspoon ground white pepper
Place the egg yolks, egg, lemon juice, mustard, salt, and white pepper in the work bowl of the food processor, blender, or bowl of a mixer; process for 10 seconds or more, until creamy and light yellow in color.