Boil the chicken breast fillet in boiling water. Take out of the water while hot and place on kitchen paper to dry. Put aside and let cool. Cut into stripes.
Clean, peel and roughly grate the radish (if you use radishes, just wash them and then rub them). Peel and halve the onion and cut into thin strips.
Now put all ingredients in a bowl. Now add the mayonnaise and mix everything together well. Finally, add salt and pepper to taste.