Bring 6 cups water to a boil. Submerge noodles in water and boil for 6-8 minutes. Stir as necessary to prevent noodles from sticking together.

While the noodles are cooking, place the peanut butter, chicken broth, sweet chili sauce, soy sauce, sesame oil, and rice vinegar in a large saucepan and whisk over medium heat until the sauce has become smooth and creamy. Remove from heat. Slice the roasted red peppers and add to the sauce. 

Drain the noodles when they are soft and chewy, and rinse with warm water. Add the noodles to the saucepan with the peanut sauce and toss together. Sprinkle chopped peanuts, scallions, and black sesame seeds over each serving.