For the salad dressing, put mustard with olive oil, some raspberry balsamic vinegar and a few fresh raspberries in a shaker. Shake well and season with salt and pepper.
Briefly toast the walnuts in a pan without fat and sprinkle with the sugar to taste and caramelize.
Wash and spin the lettuce and remove unsightly spots. Salt and pepper the steaks and fry them medium in a hot pan. Let the steaks rest for a few minutes.
In the meantime spread the salad on a plate, pour a little dressing over it and sprinkle the nuts over it. If you like, you can also slice parmesan over the salad. Cut the apple into thin slices and drape on top of the salad.
Cut the steaks into strips, arrange on the salad and serve.