Cornflour, or cornstarch as it’s known of in the States, is the finely powdered white starch extracted from maize kernels, which are soaked and ground to separate the germ from the bran. It is virtually tasteless and is used as a thickening agent. It cuts down the need for fat as, unlike other flours, it blends to a smooth cream with liquid.
Cornflour will form lumps if added directly to hot liquid. To avoid this, blend one part cornflour with two parts cold liquid until smooth, then stir the mixture into the sauce that needs thickening. Keep stirring while the sauce comes to the boil and it will gradually thicken. It’s best to cook the sauce for a few minutes longer after adding the cornflour to remove its slightly floury taste. Cornflour is also a good addition to light batters for coating fish or meat and is used in some cakes and biscuits.