Some recipes require flour or roux to further thicken the borscht. Roux () is flour and fat cooked together and used to thicken sauces. Cornstarch may be used to thicken it. Untreated starch requires heat to thicken or gelatinize. Starch slurry is used to thicken the sauce. This powder can be used to thicken soups or stews. Candlenuts are normally ground to thicken sauces. Boiled lentils and lentil stock are used to thicken most vegetarian curries. Then something starchy is added to thicken the juices. Romans used it also in cosmetic creams, to powder the hair and to thicken sauces. Plot, colour, identities thicken and dissolve. They also thicken cervical mucus and thin the lining of the uterus, enhancing their effectiveness. Rheopectic fluids, such as some lubricants, thicken or solidify when shaken. Eggs can be beaten into it to thicken it into gruel. As the disease progresses, heart muscles thicken and progressively fail.