Thaw shrimp, if frozen. Peel and devein shrimp; cut in half lengthwise. Rinse; pat dry with paper towels. Set aside.
For sauce, in a small mixing bowl stir together water, catsup, soy sauce, rice wine or dry sherry, cornstarch, honey, crushed red pepper, and ground ginger (if using). Set aside.
Pour oil into a large skillet or wok. Heat over medium-high heat. Add green onions, garlic, and fresh grated ginger (if using); stir-fry for 30 seconds.
Add shrimp. Stir-fry 2 to 3 minutes or until shrimp are opague; push to side of skillet or wok. Stir sauce; add to center of skillet. Cook and stir until thickened and bubbly. Cook and stir 2 minutes more. Stir sauce and shrimp together.