I spent 17 years working in Germany. My children have never forgotten eating "rindswurst" or "currywurst," both staple food with street vendors. Is there anything close to either in the US?
The "Frankfurter Rindswurst", a sausage made of pure beef meat was introduced to the people of Frankfurt in 1894 by the Frankfurt butcher Gref-Voelsing. The sausages were designed to meet the demands of the growing population of Jewish people in Frankfurt. The sausage may be boiled, broiled or grilled and has become one of the most famous delicacies of Frankfurt.
here in Cincinnati, we still have German-descended butchers creating authentic German sausages. It is a true blessing. I had my butcher pack an assortment in plastic seal, froze them, packed them in ice, and took Cathy a selection on a visit to Hawaii and she is still talking about them. : ) They are pretty amazing.
My suggestion would be to look for a local butcher who is hand making their own sausage in the casing.
Other than that, there are some mail order options, albeit rather expensive, available from these German food importers: