In a small bowl, beat the egg and egg yolk then blend in the milk.
Place the flour in a medium mixing bowl, season with salt and pepper, then add the milk mixture. Whisk until smooth, batter will be thin. Cover and set aside to rest for at least 4 hours.
When ready to cook, heat an omelet pan over medium heat and add the butter. When melted, add to the batter and whisk to blend.
Ladle about 1/3 cup of batter into the pan and quickly turn the pan to spread of the whole surface.
When small, glistening bubbles are seen on the surface, flip the crepe and cook the other side for about 15-30 seconds or until lightly brown.
Stack on a plate with wax paper between. May be frozen for later use.