Put the veg in a bowl and toss with 2 tbsp sea salt. Leave, covered at room temperature, for 4 hrs. Drain the veg and wash well under cold water. Drain well.

Put 100ml of the vinegar in a bowl with the mustard powder, coriander seeds, mustard seeds, cumin, turmeric and flour. Mix well to make a paste.

Heat the remaining 500ml vinegar, sugar, bay leaves and a pinch of salt until the sugar dissolves, then pour in the mustard vinegar mix, simmering and stirring for 5 mins until the mixture thickens. Fold in the drained veg, heat for 1 min taking the edge off the veg, but still retaining a bite, then remove from the heat, and pack into three 500ml warm sterilised jars. Seal and leave in a cool dark spot for six weeks or up to three months before opening. Once open, keep in the fridge and use within four weeks.