Final answer:
The desired consistency for a slurry made from cornstarch or arrowroot is similar to heavy cream. It should be smooth, free of lumps, and thick enough to coat a spoon lightly but still pourable. A common ratio for achieving this consistency is 1 part cornstarch to 2 parts cold liquid.
Step-by-step explanation:
When using cornstarch or arrowroot to make a slurry, the consistency you want to achieve is that of a liquid similar to heavy cream. This consistency allows for the slurry to be easily mixed with other ingredients without being too thick or too thin. If the slurry is too thick, it could form lumps when added to the dish, while if it's too thin, it might not thicken the sauce or soup adequately upon cooking.
The process of making a slurry involves mixing cornstarch or arrowroot powder with a cold liquid, usually water, until it's smooth and free of lumps. The ideal consistency is achieved by using a ratio of about 1 part cornstarch to 2 parts cold liquid. This results in a pourable, yet thickened liquid that can efficiently act as a thickening agent once added to the hot substance you are cooking.