1 cup thick barbecue sauce
1 medium onion, thinly sliced
2 cans (4.5 oz each) diced green chilies
3 tablespoons chili powder
1 teaspoon ground cumin
1 teaspoon dried oregano
1/4 teaspoon ground cinnamon
1 boneless pork shoulder roast, 2 1/2 to 3 pounds, trimmed
1/2 cup chopped cilantro
Combine sauce ingredients in a bowl. Place pork in crockpot; pour sauce mixture over the pork, lifting pork slightly so sauce will flow under the roast. Cover and cook on LOW for 8 to 10 hours, or until pork is very tender. Remove pork to a cutting board and chop or shred with forks. If sauce is very liquid, cook down on the stovetop until desired thickness and flavor is reached. Pour sauce into a serving bowl or leave in slow cooker; stir in the cilantro and the shredded pork. Serve with flour tortillas or split sandwich buns.
From about.com's section on Southern Food.