Place the eggs in a pot and cover them with water. Bring the water to a boil over medium heat, then reduce to a simmer for 10 minutes.

Drain the hot water and transfer the eggs to a bowl of ice water. Let them cool for 5 minutes before peeling.

Slice each peeled egg in half lengthwise. Scoop the yolks into a mixing bowl and set the whites aside on a plate.

Mash the yolks with a fork. Add the mayonnaise, mustard, salt, and black pepper. Stir until the mixture is smooth.

Spoon or pipe the yolk mixture back into the egg white halves. Top each filled half with one green olive slice.