Going to Mattern is akin to taking a trip to Bavaria while reaffirming all of your previous assumptions about the quality of German meat, i.e., it's delicious and there's a lot of it. The owners are immigrants from Germany, and they make their own sausage, something you can definitely taste. But before you start salivating over the varieties of deli meats (such as the Black Forest ham), the cheeses (such as smoked gouda and fresh Gruyere), the European foodstuffs and the sausage (bratwurst, weisswurst, spicy Polish sausage, you name it), there is something you need to do. TAKE A NUMBER. The very nice salespeople will not serve you unless you have one, and they will patiently wait until you know what you want. The pastrami is not bathed in salt and is especially tasty when served on a French roll. Or, if you like a variety of meat in your sandwich, the aptly named Poor Boy contains a generous mixture of deli slices that will keep the carnivore in you happy for the afternoon—and is priced at a comfortable $4.90 (tax included). If you get there at lunchtime, you might want to spend that 30-minute wait for your number to be called by perusing Mattern's variety of Germanic goods: imported chocolates, European beer, foreign-language magazines, freshly baked apple strudels. The place closes at a very European 5 p.m., so take it to-go if you want Mattern's bratwurst for dinner. And you will.