Boil chicken breast in water.
Cool the boiled chicken breast and shred it along the grain.
Thinly slice cucumber and radish.
Boil the noodles in boiling water and rinse in cold water.
Make Chogye noodle broth with vinegar, salt, sugar, mustard, and chicken stock.
Put noodles, chicken breast, cucumber, and radish in a bowl and pour broth.