Anne Miller wrote:
That is an interesting concept, using potato starch instead of corn starch.
Would potato starch be something like instant potatoes?
As Tereza already said, potato starch is just a starch.

Very basic household item in Finland (corn doesn’t grow well here but potatoes do!) used in many things as a thickening agent just like corn starch. It’s also commonly used in cake batter, to make the cake more fluffy and moist.
Works as a baby powder too! I bough a 500g pack of organic potato starch for something like 1,20€ when my daughter was born. I used less than half of it when she was a baby, but I wonder what it would have cost to buy actual baby powder.. More than that! And I liked the ingredient list: just organic potato starch!
Now that you mentioned the instant potato mash, I do think it would make a tasty thickener for a soup! I might have to try it some day!