Peel your hard boiled eggs.
Cut the eggs in half, length wise and scoop out the yellow centers. Place yolks in a bowl.
Mix the yolks, cream cheese, mayo, salt, pepper and mustard until well combined.
Grab your zip loc bag and fold the top of the bag down. Cut the corner off on one side of your bag.
Should look like this. This will serve as your piping bag.
Fill the bag with your egg mixture.
Pipe the egg mixture into the eggs. Clean up any spillage around the eggs to make them look neater.
Finished product. My son likes them just like this, but I like to dress them up when people come over. Great topping ideas include paprika, smoked salmon or prosciutto ham.