Thaw shrimp, if frozen. Cut shrimp in half lengthwise. Set aside.
For sauce, in a small bowl stir together water, soy sauce, and cornstarch. Set aside.
Pour cooking oil into a wok or 12-inch skillet. (Add more oil as necessary during cooking.) Preheat wok over medium-high heat. Stir-fry garlic, celery and chopped onion in hot oil for 2 minutes. Add cabbage, fresh pea pods (if using), and carrot; stir-fry for 1 to 2 minutes more or until vegetables are crisp-tender. Remove vegetables from the wok.
Add half of the shrimp to the hot wok. Stir-fry for 2 to 3 minutes or until shrimp turn opaque. Remove shrimp from the wok. Repeat with remaining shrimp. Return all shrimp to the wok. Push shrimp from the center of the wok.
Stir prepared sauce. Add sauce to the center of the wok. Cook and stir until thickened and bubbly. Return cooked vegetables to the wok. Add hot cooked noodles or pasta, green onions and thawed frozen pea pods (if using). Toss all ingredients together to coat with sauce. Cook and stir for 1 to 2 minutes more or until heated through. Garnish with cilantro and serve immediately.