If you're looking for the ultimate Bavarian experience in Northern Germany, look no further than Süllberg Almhütte. Apparently they build it each winter to sit on what is otherwise a patio area, and serve traditional Bavarian food in traditional costume. It's all very gemütlich (cozy, cheerful).
We visited on a sunny afternoon in mid-January with a party of 8 adults and 3 kids. The restaurant is really just one big room, with a bathroom, coatroom, and kitchen off to one side. The dining room is very cozy, with wooden tables and benches all smashed together, and you'll probably share a table with some strangers. (But we're all pretending to be Bavarian, so it's okay.)
I had the "F(r)isch vom Hamburger-Fischmarkt", which is a collection of smoked fish, including salmon, rainbow trout, and eel. It's served with a few thin slices of schwarzbrot (black bread), butter, shredded horseradish, and red radish. It is an impressive quantity of fish (see photo), but it was so delicious that I finished the whole thing. It was truly delicious. My daughter was able to get a small Käsespätzle which she enjoyed, and everyone else had an impressive quantity of food that they handily dispatched. Beer, coffee, and apple juice were drank.
For dessert we ordered two Kaiserschmarrn, which is a kind of shredded pancake served with nuts, raisins, and a red berry sauce. It was also incredibly delicious. Don't miss it.
The service was actually pretty good considering the chaos inside this tiny wooden building. My only real complaint was the seating (very crammed and uncomfortable) and the noise level (pretty high). If you're up for a good time, though, it's hard to beat. read more