Parmesan cheese rinds. Sal61 / Getty Images via Canva Pro.
Cheese rinds are leftover rinds from hard cheeses such as Parmesan or Romano.
They can be used as an ingredient in a soup to both thicken it and add flavour.
As you have leftover cheese rinds, pop them in the freezer until you make a soup, then add to the soup while cooking.
Remove and discard before serving.
This technique is often done in the south of Italy with minestrone.
Language notes
In Italian, the term is “crosta di formaggio” (literally, “cheese crust”).