Two weeks from now I will be in Berlin doing the typical tourist things. I have invited my 30 yo nephew, who I haven't seen in 15 years and who lives in that city working for a well known US company, to dinner probably on Unity Day October 3. I would like recommendations for restaurants that specialize in German food that are located in central Berlin (as far west as Charlottenburg - not sure how far east), is medium priced, does not have a dress code other than not be a slob, and doesn't hurry the diners.
Thanks for your help.