1 chicken carcass (from a 4-5 pound chicken)
4 carrots, quartered
4 celery stalks, quartered
2 onions, peels on, quartered
6 cloves garlic, skins on, crushed slightly
1 bay leaf
1 tsp. black peppercorns
2 tsp. salt
2 tsp. dried thyme or rosemary (or a sprig or two of fresh)
12 cups water

Place the chicken carcass, vegetables, and seasonings into a slow cooker.  Add the water.  Surround the slow cooker with kitchen towels to catch any splatter.  Cover and set on Low for 10-12 hours (I like to do it overnight).  When the stock is done, let cool slightly, then strain through a mesh sieve into a large bowl or pot, using the back of a wooden spoon to press the moisture out of the solids to get as much stock as possible.  Discard all solids.  You can use the stock immediately, but I like to let mine cool in the refrigerator so that any fat rises to the top and solidifies.  That makes it easy to scrape the fat off the top.  This recipe makes about 8 cups of finished stock, which freezes perfectly.