Start by taking the hard-boiled eggs and slicing them in half lengthwise. Carefully scoop the yolks into a mixing bowl, ensuring that the egg whites remain intact in their shells for later use.
In the bowl with the yolks, add the halved avocado. Use a fork or a potato masher to blend the yolks and avocado together until the mixture is smooth yet retains a slightly chunky texture.
Incorporate the Greek yogurt, Dijon mustard, and fresh lemon juice into the mash. Mix thoroughly until all ingredients are evenly combined, creating a creamy consistency.
Fold in the chopped chives and finely diced celery, ensuring that they are distributed throughout the mixture for added flavor and crunch.
Season the salad generously with salt and freshly ground pepper, mixing well to taste. If you enjoy a bit of spice, don't hesitate to add a pinch of red pepper flakes.
Gently scoop the egg whites out of their shells and place them onto a serving plate. Using a spoon, generously fill each egg white half with the avocado egg mixture, creating a delightful presentation.
As a finishing touch, sprinkle additional chopped chives over the top of each filled egg for a pop of color and extra flavor before serving.
Notes
For a playful presentation, serve the filled egg halves in a rustic egg carton.