Preheat the grill or broiler.

Bring a large pot of water to a boil. Add the noodles and remove from the heat. Let stand 8-10 minutes, or just until tender. Drain, rinse with cold water and set aside.

In a small bowl, combine the water, fish sauce, lime juice, brown sugar, chile sauce and peanut oil. Remove 2 tablespoons of the dressing and reserve the remainder. Brush the chicken with the 2 tablespoons of the dressing, sprinkle with salt and pepper and grill or broil until cooked through, about 8 minutes. Set aside.

Divide the noodles between 4 large bowls. Top with the romaine, grapes and carrots. Thinly slice the chicken and divide between the bowls. Drizzle with the remaining dressing, sprinkle with the herbs and peanuts and serve.