Gently cook the meat in a little oil in a frying pan and allow to cool completely.
Mix yoghurt, a little oil, mustard, ketchup, lemon juice and the Italian spice mixture in a bowl, season with salt and pepper to taste.
Drain the corn, dice the cucumbers and tomatoes. Add the cooled chicken breast pieces to the bowl with the sauce and mix everything well. Chill for at least an hour before serving.