Arrange bread cubes in one layer on a baking sheet and let them dry at room temperature overnight. In a food processor, puree the shrimp, transfer to a bowl, and stir in water chestnuts, egg white, lard, wine, ginger, scallion, salt, and cornstarch. Beat vigorously with a wooden spoon and compact it.
Form rounded teaspoons of the mixture into balls with hands dipped in cold water. Roll the balls in the bread crumbs, pressing the cubes in lightly.
Arrange them in one layer on the baking sheet. In a deep fryer, heat 2-inches of oil to 375f. In it fry the shrimp balls in batches, turning them, for 1-2 minutes or until they are golden. Transfer them to paper towels to drain. Bring the oil up to 375f again and add the shrimp balls.
Fry again, turning, until they are a deep golden. Transfer to paper towels to drain. In a small bowl, stir together the coarse salt and peppercorns for dipping. Serve with the shrimp.