Divide the cauliflower into florets and boil in salted water for 5 minutes from the moment of boiling.
Cool the cabbage, disassemble it into stumps or cut it into small pieces. Cut the onion into half rings and chop the greens. Mix, add the crushed walnuts and squeeze out the garlic.
Add salt and pepper to taste, add vinegar, mix well and put in the refrigerator for 12 hours (you can stay overnight). In principle, you can eat immediately, but the taste is unsaturated. I would recommend patience.