Cook pasta according to package directions. Drain. Set aside. Keep warm. For sauce, stir together soy sauce, plum sauce, sesame oil, and chili paste (if using). Set aside.
Pour cooking oil into a wok or large skillet. (If necessary, add more oil during cooking.) Cook and stir sweet pepper and beans in hot oil for 5 minutes. Push from center of wok. Add shrimp, garlic, ginger, and black pepper to center of wok. Cook and stir for 2 to 3 minutes or until shrimp are opaque. Stir in sauce and pea pods. Stir in pasta; heat through. To serve, top with onions and sesame seeds. Makes 4 main-dish servings.