Place eggs in tepid water and bring up to a simmer. Cook for 4 minutes, shut off heat and let eggs sit in water until water cools to room temperature.
Peel eggs and cut in half. Scoop out cooked yolks and blend with mayonnaise, mustard, chives and chopped capers and season to taste. Place egg filling in a piping bag and pipe back into egg whites. Garnish with a caper and a sprig of chive. Wrap and chill until ready to serve.
Tip: To make the yolks fine and easy-to blend, push them through a strainer, then blend with other ingredients.