In a large mixing bowl, combine the shredded chicken and cottage cheese, gently folding them together until well integrated.
Add the diced celery and sliced green onions to the chicken mixture.
In a small bowl, whisk together the lemon juice and mayonnaise (or Greek yogurt) until smooth.
Pour the dressing over the chicken mixture and fold gently until all ingredients are evenly coated.
Season with salt and freshly ground black pepper to taste.
If using optional ingredients like grapes, nuts, Dijon, or garlic powder, fold them in now.
For best flavor, cover and refrigerate for at least 30 minutes before serving.
Before serving, taste and adjust seasonings if necessary. Garnish with fresh dill if desired.