Guar Gum is a zero carb thickening agent which is perfect when you're making soups, sauces, puddings or other recipes which might normally involve cornstarch to thicken.
Guar gum is actually found in many commercial products, so this is not an 'unusual item' in terms of eating food. It is simply the ground up result of guar beans. Guar gum has little flavor, does not really affect the dish you're making in any taste manner, but does a great job of helping it thicken.
In fact, guar gum is found to thicken a dish about eight times as well as cornstarch does! So you can use a much smaller amount of guar gum and get the same end result. It's frugal and useful!
It's even found to lower cholesterol levels :)
So, where do you get your hands on guar gum? If your local store doesn't have it in the baking aisle, do a search online. There are numerous online distributors that carry guar gum. Luckily you only need a small amount for a given dish, so a reasonable purchase can last you a year or two, depending on how much you cook.
Highly recommended as an important part of every low carb household!
Lisa Shea's Library of Low Carb Books