Add water and vinegar to a pot with at least 1 inch of water to cover the eggs.

Bring the water to a boil.

Turn off the heat and let them sit for 15 minutes

Peel the eggs under cold water.

Slice the eggs in half horizontally.

Cut a small slice off the bottoms of the wide end of the eggs to make them stand up straight.

Use the sharp tip of a small knife to carefully pick out the yolks. Transfer the yolks to a bowl.

Mash the yolks with a fork. Mix in mayonnaise, mustard, and apple cider vinegar.

Season with salt and pepper to taste.

Load the mixture into a pastry bag.

Pipe the mixture into the egg whites and stand them up on a serving platter clustered together.

Cut the remaining egg whites into "petals". Arrange them in a circle on tops of the filled egg half.

Pipe a dot of filling in the middle and serve.