Heat the water, curry powder and stock cubes in a the pan until rapid boil. Chop and add onion cook until onion is soft. Mix cornflour with a liittle additinal water until you have a thin liquid at this stage you can add slowly to the curry sauce to thicken. Take care when adding the cornflour to avoid lumps. Trial and error or personal taste will dictate how much to thicken. Hope you enjoy your sauce. Tha addition of cooked chicken or veg makes a simple speedy meal