Prepare an ice bath and transfer the eggs to an ice bath for 5 minutes before peeling.
Slice the peeled hard-boiled eggs in half and place the yolks in a small bowl to make the filling.
QUICK PICKLED ONIONS
Add all of the ingredients to a non-reactive bowl (glass or plastic). Toss and let sit for about 20 minutes.
MAKE THE FILLING
Add the cream cheese and the caper liquid to the reserved egg yolks.
Using a hand mixer, mix on medium-high until the mixture is smooth and creamy.
Add a little more caper juice if the mixture seems too thick.
FINAL TOUCHES
If you are using the piping bag and the number 21 star tip, assemble and fill the piping bag with the filling mixture.
Alternatively, use a freezer or sandwich bag. Fill the plastic bag with the egg mixture filling. Cut off one corner, making sure the opening is about the width of a pencil.
Pipe the filling into each egg white half.
Slice the salmon into small pieces that can fit on top of the eggs. I make mine about the size of the first knuckle of my index finger.
Place a small slice of salmon, 2 to 3 capers, and a few pickled red onions on top of each egg.
Chill until you are ready to serve them.
RECIPE TIPS
You can make the filling the day before and store in an airtight container in the fridge. For the best results assemble the eggs right before you serve them.