Put the water in a large stainless-steel or enamel saucepan or preserving pan, add the salt and bring to the boil. Add the prepared vegetables and the red chillies and cook on low heat for 5 minutes. Pour into a colander, rinse well under cold water, then drain very well on paper towels or a clean tea towel.
Meanwhile, to make the sauce for the pickle, put the sugar, ﬂour, allspice, ground ginger, curry powder, turmeric, mustard powder and cayenne pepper in a bowl. Add 3–4 tablespoons of the vinegar and mix to form a thick spicy paste.
Put the paste, the remaining vinegar and the peppercorns in a stainless-steel or enamel saucepan and bring to the boil, stirring continuously. Reduce the heat and continue to cook, stirring continuously, for 3–5 minutes, or until the sauce thickens. Remove the pan from the heat and leave to cool, stirring occasionally to prevent a skin from forming.
Put the drained vegetables in a bowl, add the sauce and mix together. Cover the bowl and leave to stand for 24 hours.
The following day, stir the piccalilli again to coat the vegetables evenly, then spoon into clean, dry jars and cover with vinegarproof lids. Label and date the jars and store for two to three months in a cool, dark, airy cupboard to allow the flavours to develop before eating.