While I was in Germany, I learned several of the dishes that were native to the country. This is generally difficult with any modern culture, as they tend to absorb cooking skills or recipes from other countries. But there is one recipe that is distinctly German: Rouladen.
This meat dish really means "rolled", or rolled meat. The versions that I have had reflect regional differences, as in the Rhineland they roll just bacon and mustard, in the Pfalz they roll bacon, mustard and pickles, and in Bayern they roll in a bread stuffing. The meat is then slow-roasted. The smell is exquisite, the taste even more so. If you are looking for a good Crock-pot dish, this simple dish will knock your socks off.
The meat can be thinly sliced, but should be no more than a half-inch thick. Anything thicker will be difficult to roll. Ideal meat to use would be a Pot Roast, as it is not highly valued for flavor as steak, and there for less expensive. Also, your local butcher or megamart meat department should be able to slice it for you.
Bacon can be of your choosing. I prefer the fatty bacon in order to give the proper flavor. But I have used turkey bacon, and it works well enough. In fact, there is less liquid with turkey bacon, so if you don't like the liquid cleanup afterwards, that may be a good low fat alternative. The basic concept is that bacon, or some other fatty food, is rolled into the meat. This keeps the meat moist when it roasts. This is why bacon is used, or a bread stuffing with plenty of butter.
If you choose to use a pickle, I would highly recommend either buying German Pickles from a German food store, or using bread and butter pickles. You don't want to use Dill, because it will drown out the flavor, and you don't want to use sweet for the same reason. Something mildly sour is fine.
If you choose to use a stuffing, you can use any that you wish. I made a beef stuffing with beef broth, but as you are already using bacon, a pork stuffing would be fine. If desired, you can also add some minced celery, onion, and even garlic if you so desire.
For mustard, I highly recommend either getting a sharp German mustard, or a good deli mustard with whole mustard seeds. You can use the generic yellow mustard, but the flavor isn't as strong.
Finally, roll the meat together with the stuffing in the middle. Initially I used to put toothpicks in, but have found since that the rolls will seal themselves. Slow roast them for at least 5 hours. That raises the internal temperature high enough to be sure all nasty bugs are dead.
Once done serve with either potatoes, potato dumplings, or spaezel and Jaegersosse gravy, or sauerkraut. Which, of course, depends again on the region you are emulating. Jaegersosse is a brown gravy with mushrooms, and very common in the Rhineland - Pfalz area, or the Black Forest. Sauerkraut is common all over Germany, but is prepared differently. For the Rhineland-Pfalz area up to Hessen, they use wine grapes to sweeten it. In Bayern (Bravaria), on the other hand, they add gound meat to give it a more savory flavor. To each their own, but I prefer the sweet.
All together, if prepared correctly, the Rouladen can be eaten without any condiments. The flavor is almost perfect, not needing any salt or pepper. It's great for a cool fall day, or a cold winter dinner.