Binding your sauce
We will use a technical term here, liaison (you can find out the meaning of cooking terms such as this, in the glossary.) it is used to denote certain ingredients that are used to thicken sauces, stews and soups. The most common liaisons are...
In a similar manner to our roux above the term kneaded butter refers to a mixture of butter and flour, but this time in very different proportions: twice as much butter as flour is used. The butter is not melted, but mixed with the flour on a plate to make a paste. Small pieces of this cold mixture are then dropped into cooked dishes, such as stews, where the quantity of liquid is unknown, making it difficult o judge how much flour should be used.
The kneaded butter is added to hot (but not boiling) liquids. As you do so, the butter will melt and the flour will be absorbed into the liquid. Once it has melted you can turn the heat up to see if it was enough to thicken the dish. If not turn down the heat and repeat.
Arrowroot or cornflour
Mixed with a little water to make a runny paste, arrowroot or cornflour can be used as a liaison. In fact this mixture has another technical term, a fécule. To use it, take the pan of food off the heat, stir in the fécule and then put back on the heat and bring to the boil and the liquid in the dish should thicken to make a nice sauce.
Egg yolks and cream
For a creamy consistency a mixture of egg yolk and cream can be blended into a dish. Just add a little at a time to a small quantity of the liquid from the dish. When all the egg/cream mixture has been blended, then stir it gradually into the main dish. Reheat, stirring continuously, but do not bring to the boil. The egg yolks will cook slowly and result in a distinctive creamy sauce.