Peel cucumbers if desired, slice lengthways, scoop out seeds and discard them, then slice the cucumber. Cut onions in half and slice. Combine all ingredients except cornflour. Boil well for a good 20 minutes (I put lid on to bring to bring to boil, but take off before moisture drips into pickle and dilutes it). Combine cornflour with 1/4 of cup of extra vinegar, add and stir for 5 minutes or until it thickens. This recipe was submitted by a Tui Time reader.