Lightly tap each egg with the back of a spoon to make a hairline crack. Place the eggs in a large saucepan and cover with cold water. Bring to a simmer and cook over medium heat for nine minutes. (Start timing as soon as the water begins to simmer.) Drain immediately and set the pan and eggs under cold running water for one minute. Drain again and vigorously shake the eggs in the pan to loosen the shells. Peel the eggs and slice in half lengthwise.

Scoop out yolks, reserving half for another use. Set aside the whites. In a small bowl, mash the remaining yolks. Mix in breadcrumbs, sour cream, chives or scallions and mustard. Season with salt and pepper. Spoon the yolk mixture into the hollows in the egg whites and garnish with a sprinkling of paprika. Arrange on a platter. (The eggs can be prepared ahead and stored, covered, in the refrigerator for up to two days.)