Mike Chiarello- Napa Style- Doing it today.

Ingredients
Serves: 6

2 medium onions, peeled
2 tablespoons extra virgin olive oil
Gray salt and freshly ground pepper
1-1/2 teaspoons finely chopped fresh sage
1/2 cup water
4 pounds pork leg or shoulder, at room temperature
About 1/4 cup Fennel Spice (make it, or buy it)

Directions
Thinly slice the onions. Heat the olive oil in a large saute pan over medium heat until hot. Add the onions and a pinch of salt and pepper. Reduce the heat to medium-low and cook for about 1 minute. Add the sage and cook until the onions cease throwing off water, about 3 minutes. Add the water, cover, and cook until the onions are very tender, about 10 minutes. Uncover and saute until the onions are very soft and the pan is dry again, about 2 minutes. Season well with salt and pepper.
Preheat the oven to 275 degrees. Peel back the pork skin and spread the onions directly on the fat layer. Fold the skin back over the onions and tie closed with kitchen string. Season well all over with the fennel spice.

Arrange the meat on a rack in a roasting pan (or using the Cocorico, see below) and cook until the meat is very tender, 6 to 8 hours. It is ready when it pulls away easily if picked at with a pair of tongs. It is often easiest to cook the meat overnight, or put it in the oven in the morning and let it cook all day. It does not need to be attended.

On the Cocorico
You can also roast the pork using our Cocorico! Prepare the meat as instructed above but don’t add the onions before tieing the meat —you’ll add them later, and can prepare the onions while the roast is cooking. After tieing the meat with kitchen string and seasoning it with Fennel Spice Rub, set the roast on the Cocorico by "skewering" it over the cone through the side of the roast that you cut to butterfly it for seasoning. Add 3/4 cup water to bottom of pan and place cocorico and roast in the oven. Cook time will decrease by about 1 hour because the it will cook from the inside too!

While the pork is roasting on the cocorico, prepare the onions as instructed above, sliced about 1/4" thick. In last hour of cooking, skim off the fat that is in the bottom of the cocorico. Place onions in bottom of cocorico with the pork for the last hour of cooking.

Variations: This dish can be simplified or made more elaborate depending on your taste. You can omit the onions and simply season the meat with the fennel spice. You can roast aromatic vegetables until caramelized and add them to the bottom of the roasting pan. Or you can add another layer of flavor to the onions: mince fresh rosemary and fruits such as oranges, kumquats, Meyer lemons, apples, pears, or quince, and cook with the onions.
Here is a link for fennel spice rub.
http://www.napastyle.com/recipe/recipe.jsp?productId=2806