How to Make It
In a large bowl, cover the rice noodles with water and let stand until pliable, about 20 minutes.
In a mini-processor, combine the lemongrass, sugar, garlic, ginger, chile and oil and process to a paste. Scrape the mixture into a bowl and stir in the lime juice and fish sauce. Put the chicken in a large shallow bowl and add 1/4 cup of the lemongrass mixture, turning to coat the chicken. Marinate for 20 minutes. Stir the water and cilantro into the remaining lemongrass mixture.
Light a grill. Cook the noodles in a pot of boiling water, stirring, until just tender, about 2 minutes. Drain and return to the pot. Rinse with cold water and drain again, then repeat the process once more. Let the rice noodles dry, lifting them to separate the strands.
Grill the chicken over a medium-hot fire or in a preheated grill pan for 3 to 4 minutes per side. Let cool for 1 to 2 minutes, then cut the breasts into thick strips. Toss the rice noodles with the lemongrass dressing and the peanuts, top with the chicken and serve.