In a large mixing bowl, combine the cottage cheese, chopped hard-boiled eggs, mayonnaise, and Dijon mustard. Stir until well mixed.
Add the finely chopped celery, sliced green onions, garlic powder, salt, and pepper. Mix until all ingredients are evenly incorporated.
If using, fold in the fresh dill or parsley for added flavor.
Taste and adjust seasoning if necessary.
Cover the bowl and refrigerate for at least 30 minutes to allow the flavors to meld.
Serve chilled on a bed of lettuce, in a sandwich, or with crackers.