Put the vegetables in a suitable bowl, mix and grind.
In a small saucepan, pour vinegar, vegetable oil, add sugar and salt. Let it boil and cook until the salt and sugar are dissolved.
Pour boiling marinade over the cabbage, pepper and mix thoroughly, first with a spoon to avoid burns, then with your hands. Add mustard at the same time.
Cover and leave to infuse for 24 hours at room temperature.
The salad will be ready for use in a day. Store in the refrigerator.
