If you want to find out how to cook brine with kidneys, look for a recipe in Russian national cuisine. Traditionally, brine is boiled with beef kidneys, for example, brine with kidneys and pearl barley. A modern version is a Leningrad-style brine with kidneys. Such a brine with kidneys and rice is prepared. Or you can also cook brine from pork buds - the soup will turn out to be no less tasty.