Start by boiling the eggs. Place them in a pot, cover with cold water, and bring to a boil. Once boiling, cover and remove from heat, letting them sit for 10-12 minutes. Afterward, transfer the eggs to an ice bath to cool.
Once cooled, peel the eggs and chop them into small pieces. If you’re discarding yolks, remove 4 and set aside the remaining yolks.
In a large mixing bowl, combine the Greek yogurt, fat-free mayonnaise, and Dijon mustard. Whisk until smooth and well combined.
Add the diced celery, sliced green onions, and dill to the yogurt mixture. Stir to incorporate all the flavors.
Gently fold in the chopped eggs (and yolks if you’re using them) into the bowl. Be careful not to mash the eggs completely; you want to maintain some texture.
Sprinkle in the salt, pepper, garlic powder, and optional sugar. Mix gently until everything is well combined. Adjust seasoning as needed.
Cover the bowl and refrigerate for at least 30 minutes to let the flavors meld. Serve on whole-grain bread, in a wrap, or on a bed of greens.