Place the eggs in a medium saucepan and cover with cold water by at least an inch. Bring to a gentle boil over medium-high heat. Once boiling, remove from heat, cover, and let sit for exactly 9 minutes for perfectly set yolks.
Prepare an ice bath while eggs are cooking. When the timer goes off, transfer eggs immediately to the ice bath and let cool for 5 minutes to stop the cooking process and make peeling easier.
Gently tap each cooled egg on a hard surface and roll to create cracks all around, then peel under cool running water to help remove the shell cleanly.
Chop the peeled hard-boiled eggs into small, uniform pieces - about ½-inch pieces work well.
In a large mixing bowl, combine the cottage cheese, mayonnaise, and mustard. Stir thoroughly until you achieve a smooth, creamy consistency.
Fold in the diced celery and sliced green onions, stirring gently to distribute evenly throughout the creamy base.
Add the chopped eggs to the mixture, folding them in with a gentle touch to maintain some texture while ensuring everything is well combined.
Season with salt and freshly ground black pepper to taste. If using, add fresh dill, garlic powder, paprika, or any optional ingredients you've chosen.
For best flavor development, cover the bowl and refrigerate for at least 20 minutes before serving, though 1-2 hours will yield even better results as the flavors meld.
