There is a recipe in the book Beyond Nose to Tail by Fergus Henderson for what he calls Trotter Gear. It is a rich pork stock that sets up like jello, and it can then be used as an ingredient to intensify anything from slow cooked stew or casserole to terrines and duck confit giving them additional flavor and body. An added benefit besides the rich flavorings is that the gelatin contains natural glucosamine and chondriton, necessary for supple joints.
The recipe is fairly simple. I don't own the book yet (only his first one, The Whole Beast: Nose to Tail Eating) so this recipe is from another blog.
* 6 pork trotters (pigs' feet)
* 2 leeks, roughly chopped
* 2 onions, roughly chopped
* 2 stalks celery, roughly chopped
* 2 carrots, roughly chopped
* 1 head garlic, roughly chopped
* 2 bay leaves
* 12 black peppercorns
* 2 sprigs thyme
* 1 cup Madeira (I used Marsala because that's all the grocery store had)
* 1 1/2 quarts stock (I used a quart of chicken stock and a pint of pork stock)
Clean and chop all the vegetables coarsely and put in a large pot with trotters. I'm using my crock pot. (My trotters came cut in smaller pieces and the recipe doesn't specify cutting or not.) Add wine, herbs, peppercorns and stock. Cover, bring to a boil, reduce heat to a simmer and cook for about 4 hours. You could also braise the mixture in the oven at 325ºF for about four hours.
I have to tell you, the smell as it is simmering is awesome!
Allow the stock to cool enough to handle. Strain the contents into another clean pot or large bowl, and discard all the vegetables. Pick the meat and skin from the trotters, discard the bones (there will be many!) and keep all those weird, gross looking wobbly bits – they are the magic here. Chop the meat and skin and add to the stock. (I chopped mine in a food processor.)
Unless you are using it within a day or so, put the cooled contents into freezer containers and freeze until needed. Many recipes will not need more than a quarter cup and up to one cup of Trotter Gear added for additional flavor and sufficient thickening, so I froze mine in small containers, some with just the stock, and some with the minced solids added.
You could also line an ice cube tray with plastic wrap and freeze in cubes. Put the frozen cubes in a zip lock bag or vacuum seal them and store in the freezer.
Notes: When I make this again, I will first boil the trotters for about 5 minutes to get rid of the scum, which wasn't too bad in a crock pot but could be plentiful in a soup pot on the stove. Then I'd rinse them and follow the recipe!