Prepare the vegetables. Break the cauliflower into small florets, trim the beans and cut into short lengths. Peel and quarter the shallots or onions. Cut the courgettes into half or quarters lengthways then thickly slice. If using cucumber cut in half lengthwise, scoop out and discard the seeds then cut in half again and slice.
Layer the vegetables in a bowl sprinkling with the salt as you layer them. Toss together to coat with the salt. Cover and allow to stand for 24 hours.
Drain the vegetables and rinse very well in cold water. Drain and allow to dry.
Mix the flour, sugar, mustard powder, turmeric and ginger together in a pan with a little of the vinegar to form a smooth paste. Make sure that you get the mixture lump free at this stage.
Gradually stir in the remaining vinegar. Cook over a low heat stirring until the mixture comes to the boil and thickens.
Add the vegetables and cook gently for 2-3 minutes. Spoon into hot sterilised jars and seal.