This recipe will keep in the fridge for a few days. You could do it without the mayo or yoghurt to make it vegan, but I find that just a small amount brings it all together nicely.
Peel and grate the kohlrabi and the carrot and put in a large bowl. Chop the green onion and add it to the bowl with the walnuts and the raisins. Add the juice of the lemon and the mayo and stir well to combine it all. Season to taste. You could also add a little handful of chopped parsley.