Cook the vermicelli noodles according to package instructions until tender. Rinse under cold water, drain, and set aside.
In a saucepan, heat the chicken broth over medium heat until simmering. Season with fish sauce, sugar, salt, and pepper to taste.
Thinly slice the chicken breast and season with salt and pepper. Set aside.
Beat the eggs and cook them into thin omelettes. Roll them up and slice into thin strips. Alternatively, poach the eggs until the whites are set but the yolks are still runny. Set aside.