Place the eggs in a single layer in a saucepan and cover with cold water by 1 to 2 inches. Heat over high heat until the water comes to a rolling boil. Cover the saucepan with a lid, cook for 30 seconds, then remove from the heat and let stand for 12 minutes. Transfer the cooked eggs to a bowl of ice water using a slotted spoon and leave for 5 minutes.
Meanwhile, mash the avocado, mayonnaise (or yogurt), and lemon juice in the bottom of a medium bowl.
Peel and chop your hard-boiled eggs, and then add them to the bowl.
Stir in the celery and chives. Then, season with salt and pepper to taste.
