1. Prepare noodles according to package directions. Drain well; rinse with cold water for 30 seconds. Set aside.
2. Combine peanut butter, soy sauce and red pepper flakes in bowl with wire whisk. Set aside.
3. Heat oil over medium heat in a wok or large frying pan. Add shrimp, tofu, pork or chicken. Stir-fry 1 minute or until done.
4. Add softened noodles and peanut butter mixture to wok or large frying pan. Stir-fry 3 to 5 minutes. Toss with green onions, carrots, cilantro and red bell pepper, if desired. Garnish with chopped peanuts, if desired. Serve immediately. Makes 2 to 4 servings.