Grandmother's Mustard Pickles

In a large bowl, combine the cucumbers, onions, cauliflower and bell pepper. Stir together the salt and water; pour over the vegetables. Cover, and let stand overnight at room temperature. Sterilize 5 (1 quart) jars with lids and rings. Keep in a hot water bath until needed. Transfer the vegetables and brine to a large pot and set over medium heat. Bring just to a simmer, but remove from the heat before they come to a boil. Pour into a colander and drain thoroughly. Dry out the large pot and stir together the flour, mustard powder, sugar and turmeric in it. Stir in just enough apple cider vinegar to make a smooth paste, then stir in the remaining vinegar. Bring to a boil, stirring frequently, and boil until thick and creamy, 10 to 15 minutes. Add the vegetables and simmer over medium heat until vegetables are tender but not overcooked, 5 to 10 minutes. Pack into hot 1 quart jars, filling to 1/2 inch of the rim. Seal with lids and rings. Process in a bath of simmering water for 10 minutes, then cool to room temperature. Refrigerate any jars that do not seal properly and consume within two weeks.