Chop the hard-boiled eggs into small pieces and place them in a large mixing bowl.
Add mayonnaise, mustard, relish, and green onions to the bowl.
Stir everything together until well combined. Season with salt and pepper to taste.
Refrigerate for at least 1 hour before serving to let flavors meld.
Serve on toasted bread, croissants, lettuce wraps, or crackers.
Garnish with paprika and chopped parsley if desired.