Chipotle Carnitas Recipe

Chipotle buys their pork from Niman Ranch, and you can find their carnitas recipe in the Niman Ranch cookbook. I can't remember the exact recipe word for word, but here's the basic idea.

3.5 (or so) lbs Pork Shoulder, rolled and tied
1 Onion, halved and sliced (I think?)
2 cloves Garlic, chopped
2 Dried Chipotle chilis
5 Cloves
2 teaspoons (?) Dried Oregano
1 teaspoon Ground Cinnamon
Beef Stock

I may be leaving something out, but that's the most important stuff, I think

Season the pork liberally with salt and pepper. Brown on all sides in canola oil. Remove.

Add onions, cover, and cook until softened stirring frequently. Add the garlic and cook uncovered. Add beef stock (enough to come halfway up the pork). Add back the pork. Tie up the spices in cheese cloth and add to pot. Bring the liquid to a boil and immediately move to a 300 degree oven, covered with foil. About 3 hours (??) and it should be tender.