Boil the eggs. Fill a large pot with 8" of water and gently add in the eggs. Add the white vinegar to the pan of eggs. Bring the water to a rolling boil. Prepare the ingredients While the water is boiling. Finely chop the parsley, if using. Cut and juice the lemon. Turn off the burner. Cover the pot and leave it on the stove. Allow it to sit for 12 minutes.
Drain the eggs and rinse them in cold water. (This stops the cooking process).
Peel the shells from the eggs. Rinse each under cold water to remove shell remnants.
Carefully cut the eggs in half lengthwise.
Gently remove the yolks from the eggs and place them in a medium-size mixing bowl.
Set the cooked egg whites aside on a plate.
Add all of the remaining ingredients to the mixing bowl with the egg yolks.
Thoroughly mix the ingredients by mashing and mixing until you have a consistent thick but creamy mixture.
Use a spoon and fill each egg half with a rounded heap of the mixture.
Sprinkle the parsley on top.
Serve immediately. Keep them cool. They can be covered and refrigerated for up to three days.