Cook rice noodles according to package directions, adding peas for the last 30 seconds of cooking. In a large bowl, whisk together the soy sauce, sesame oil, chili paste (if using) and peanut butter. Add the diced roasted peppers to the bowl and stir to combine. Drain rice noodles and transfer to the bowl. Toss to combine. Sprinkle chopped cilantro on top and serve warm.