Place eggs in saucepan and fill with cold water to cover. Bring to a boil over medium high heat. Cover, remove from heat and let stand for 15 to 20 minutes.
Drain and run under cold water until chilled. Refrigerate for at least 2 hours or up to 7 days.
Place peeled, hard cooked eggs in a bowl and using a fork or potato masher, mash eggs until finely chopped.
Stir in yogurt, mayonnaise, Dijon mustard, salt and pepper until smooth.
Add celery and green onion (if using) and stir to combine.
Spread over your favourite bread, stuff into pita halves or scoop some onto your favourite salad greens.
