Using flour alternatives for thickening

Finding foods we can all eat without gluten is difficult. But it becomes exceedingly more difficult with all the hidden sources of gluten.  I went to make one of my sisters recipes, Rice-a-weanies, which calls for cheddar cheese soup, milk, rice, and hot dogs. Seems pretty simple right? And everybody loves it.  We’ve had it before, but not since we went gluten free.  I get all of the stuff together and then check the labels just in case... A good thing too because right at the top of the ingredient list on the cheddar cheese soup is... you guessed it!  Wheat flour!  Ugh.  So my whole dinner plan is ruined. So I google homemade cheddar cheese soup and find a good recipe at busymominthekitchen.com. Only one problem: still calls for all purpose WHEAT flour. So BACK to google.  How to use corn starch to replace flour as a thickener, which brought me to Celiacdisease.about.com.  It said to substitute ½ as much corn starch as the recipe calls for flour. So if it calls for 2 tablespoons, only use one tablespoon. Also, don’t add the cornstarch directly, dilute it with water to make a sort of slurry and then add it in. Well, now we are back in business. Too bad it’s too late for me to go back to the store today.  Curse you gluten! Get out of my food!