In a small bowl, combine all the marinade ingredients and season with a little salt and pepper. Place the steaks in a non-metallic dish and pour over the marinade. Cover with cling film and pop in the fridge for 30 minutes.
Arrange the lettuce, cherry tomatoes and radishes on your serving plates, sprinkle over the sweetcorn and crumble over the Feta cheese. It's nice to leave some chunks of Feta so don't break it down too much.
In a small bowl, combine the dressing ingredients and leave to one side.
Pre-heat the griddle or frying pan and place the steaks in the pan. As the steaks are very thin, a minute on each side will cook them through.
Remove from the pan and allow to rest for a minute. Slice the steaks into thin slices and arrange on top of the salad.
Drizzle the salad with the dressing and serve.