Halve the eggs lengthwise and transfer the yolks to a mixing bowl. Set 20 egg white halves on a platter, cover, and refrigerate. This recipe uses 12 egg yolks, but only yields enough filling for 20 halves; reserve the extra 4 whites for another use.
With a fork, mash the yolks to a smooth consistency.
Add the mayonnaise, sour cream, truffle oil, and salt, and mix until smooth. (You can also do this using an electric mixer with a whip attachment.) Taste and season accordingly.
Spoon the mixture into a pastry bag fitted with a plain or large star tip, then pipe the mixture evenly into the egg white halves. Or fill the eggs with a spoon, dividing the filling evenly.
Top each egg half with a tiny sprinkle of black lava salt, a grind of fresh-cracked black pepper, and a chive flower, if using.
Tip
Specialty salts, such as black lava salt or other gourmet varieties, are available both online and in specialty and gourmet food stores.
