Sweet mustard pickles

Name: Sweet mustard pickles
Cook time: 45 min
Total time: 45 min
Cuisine: European, British
Ingredients: 1/2 cup (140g) coarse cooking salt; 2 cup (500ml) boiling water; 1 litre (4 cups) cold water; 500 gram cauliflower, chopped coarsely; 4 medium brown onions (600g), chopped coarsely; 2 lebanese cucumbers (260g), unpeeled, chopped coarsely; 3 cup (750ml) cider vinegar; 2 cup (440g) white sugar; 1 tablespoon mustard powder; 1 teaspoon curry powder; 1 teaspoon turmeric; 1/3 cup (50g) cornflour; 2 tablespoon water