Peel and roughly grate the beetroot and carrot. Coarsely grate the apple as well. Mix a dressing out of the vinegar, oil, salt and pepper and mix with beetroot, apple and carrot. Chop part of the walnuts and fold into the salad, garnish with the other walnuts.
If you want more bite in the salad, you can roughly dice the apple.
Do not use balsamic vinegar for the dressing, it is too sweet.