Remove and discard the cabbage cores and finely shred the leaves. Slice the onion wafer-thin using a mandolin if you have one. Peel the mango and cut the flesh into matchsticks.

Put the mustard, vinegar and sugar in a jam jar. Screw on the lid and give it a good shake. Add the oil, salt, pepper and hot sauce. Shake again then pour into a large serving bowl. Toss in the cabbage, onion, mango and chillies and mix well. Taste for seasoning.