Having been a chef for over 40 years, I am still surprised by the number of different ways, different people, have of thickening various things. After many years of using most of the 'thickening agents', I was working with a top chef from the 'Carlton Club' and the Head Chef, from the 'Coldstream Gaurds', when, strangely, this subject came up. After discussing a large number of tasty and tasteless ways of achieving the end result, we all seemed to agree, that the simplest, 'tasteless' way of thickening any soup, stew, curry, gravy, etc, is to use Cornflour. Mixed with cold water, then when added to the hot liquid, it will thicken the liquid as the temperature rises, while stirring. Just add the required amount until your specific thickness is achieved. If you add to much just add some more water, so as to reverse the process. You can either make the amount of the 'thickening agent', as required, or alternatively, as we had all settled on, make a quantity, when completely mixed, pour into a clean, reusable, plastic squeezy bottle(that may previously contained a type of sauce or other dressing), and you have your thickening agent ready to be used when you need it. However, remember to give it a good shake prior to adding it to the liquid you are thickening. And it can be stored in or out of the refrigerator, which ever is your personal preference.