LIQUID FLOUR. You may notice that when using a thickener for a sauce or soup, I do not use a roux (the cooking of margarine with flour till thick and golden brown). Instead, I use a liquid flour, obtained by combining a measured amount of water or broth and flour in a jar with a tight-fitting lid. It is shaken vigorously till blended, then added to the sauce or soup, which is then stirred continuously over medium heat till thickened. I find this method easy, convenient and trouble-free.
When combining the water and flour in the jar, always add the water first so that the flour won’t stick to the bottom of the jar.
Do not put hot liquid in the jar; it could explode when shaken. Rinse jar immediately after using to make cleaning easier.