Put 4 large pork shanks into a large pot, and cover with brine solution made from 2 T salt per 1 quart of water. Leave in refrigerator overnight.
Cover the bottom of a roasting pan with one layer of thickly sliced onions. Discard the brine that the pork shanks were soaking in and place the shanks on top of the layer of onions in your roasting pan. Season with garlic salt and pepper.
Slow roast the pork shanks at 300 degrees until they are 160 degrees and very tender with a brown, crispy skin. This will take at least 3 - 5 hours depending on the size of the shanks that you use. Baste with a good amber or dark beer (not guiness) every 30 minutes. The drippings in the bottom of the pan make an excellent gravy!
Serve with Spatzle and Red Cabbage for a great German meal!