Cook chicken in just enough water to cover and bring to a boil. Cover, reduce heat and simmer chicken is just done. When cool enough to handle shred into bite-size pieces.
Bring a large pot of water to boil and cook rice noodles until tender (6 to 8 minutes) Drain and rinse.
Combine vinegar, fish sauce and sugar and whisk until sugar dissolves. Add the chicken and rest of the ingredients and toss to combine.