Marius Johnston's Smoked Carnitas

Pork 

***PART I***
1 medium Boston butt
1 large onion; quartered
2 tablespoons ground coriander seed
2 tablespoons ground cumin seed
1 tablespoon oregano
3 chipotles in adobo sauce
2 bay leaves
1 can beer
water to cover
***PART II RUB***
Dry rub the butt
5 tablespoons black pepper
5 tablespoons paprika
1 tablespoon chili powder
2 tablespoons celery salt
2 teaspoons dry mustard
1 bottle Grandma's chili powder; (3 oz)
1 ounce pasilla chili powder; (this is a must)
2 teaspoons cayenne pepper

Part I. Combine Part I ingredients in pot and lightly boil for 1 to 2 hours. Save butt simmer liquid. Combine rub ingredients. Remove the butt after 1 to 2 hours cooking and dry rub it with Part II ingredients. Put butt in a Ziploc bag, in the refrigerator overnight. Next day fire up your smoker. I used a Brinkmann "smoke and Grill" with the door on the side, water tray in but no water (foil wrap the water tray). I smoked the butt with mesquite coals at 250F for about 8 hours. It depends on whether you want to pull it or cut it--longer if you want to pull it. Every hour I put foil wrapped mesquite chips on the coals. I also mopped with the butt liquid every hour just prior to the addition of the chips.