Blunzngröstl also known as Blunzengröstl refers to an Austrian traditional dish made of pan fried potatoes and blood sausage called Blutwurst in German which is generally served with freshly grated horseradish (horseradish is Meerrettich in German).
Blunzen refers to a black sausage which is made of blood and lard. This sausage is often cut and fried with some bacon and potatoes.