Cook noodles according to package directions (do not overcook). Rinse noodles thoroughly with cold water to stop cooking and remove salty residue; drain. Place noodles in large bowl; toss with oil.
Place sesame seeds in small skillet. Cook over medium heat about 3 minutes or until seeds begin to pop and turn golden brown, stirring frequently. Remove from heat; set aside.
Combine chicken broth and peanut butter in small bowl with wire whisk until blended (mixture may look curdled). Stir in soy sauce, green onions, bell pepper, jalapeno pepper, garlic, and red pepper flakes.
Pour mixture over noodles; toss to coat. Cover and let stand 30 minutes at room temperature or refrigerate up to 24 hours. Sprinkle with toasted sesame seeds before serving.