A traditional English mustard pickle, Piccalilli is made from a variety of vegetables which are first soaked in brine, then pickled in vinegar. The finished pickle is yellow in colour owing to the presence of turmeric and mustard. The pickle may be served immediately it has cooled, but it improves with keeping and may be stored for up to 3 months. Piccalilli is usually served with cold meats. Use firm red tomatoes if green ones are unavailable. About 3 pounds. Place the cauliflower, cucumber, pearl onions, Spanish onion and tomatoes in a large bowl. Sprinkle with salt over the vegetables and set them aside for 4 hours. Drain the vegetables in a colander and discard the liquid. In a large saucepan, bring the vinegar to a boil over high heat. Add the vegetables and reduce the heat to low. Cover the pan and simmer the vegetables for 15 minutes or until they are almost tender when pierced with the point of a sharp knife. Remove the pan from the heat and drain the vegetables in a colander. Discard the vinegar. Place the vegetables in a large bowl. Sauce: To make the sauce, pour the vinegar into a medium sized pan and stir in the mustard seeds, ginger, garlic, peppercorns, turmeric, mustard and sugar. Place the pan over low heat and stir to dissolve the sugar. When the sugar has dissolved, increase the heat to moderate and bring to a boil, stirring frequently. Reduce the heat to low and simmer the mixture for 15 minutes. Remove the pan from the heat and strain the liquid into a medium sized bowl. Discard the flavourings left in the strainer. Rinse the pan and return the strained mixture to it. Stir in the flour mixed with the water and place over moderate heat. Bring the sauce to a boil, stirring constantly, and boil for 2 minutes. Remove the pan from the heat and pour sauce over the vegetables. Mix the vegetables with the sauce with 2 spoons, tossing until coated with sauce. Spoon into clean, warm, dry jars with screw top lids. Spoon any sauce remaining into the jars, so they are completely full. Place lids on the jars and half screw into position. Set jars aside until completely cold. Screw lids on firmly and store the jars in a cool, dry place.