Thinly slice scallions, separating the green and white portions; set the green aside for garnish. In a medium bowl, combined the sliced white portions of scallion with the ginger, garlic, horseradish, sherry, soy sauce, tomato sauce and brown sugar. Mix well and set aside.
In a wok or large skillet, heat the oil over medium-high heat until hot but not smoking. Add the shrimp and cook, stirring, until just pink, about 3 minutes.
Stir in the sauce mixture, crushed red pepper and black pepper. Cook, stirring frequently, until the shrimp are opaque and the sauce is heated through, 3 to 5 minutes. Transfer to a large serving dish or platter and serve hot or at room temperature, garnished with the parsley, cilantro and the reserved sliced scallion greens.