To make the sauce combine vinegar, lime juice, chipotle, adobo sauce, garlic, cumin, oregano, black pepper, salt and cloves in a blender or processor on high speed until smooth.
Insure all excess fat is trimmed off and cut into 6-8 pieces.
Heat oil in a heavy skillet over medium high heat.
Sear all sides of the meat to get a nice crust.
Place meat in slow cooker.
Cover with with sauce.
Pour in broth and add bay leaves.
Cover and cook 5 hours on high (or 8 hours on low).
Remove the bay leaves.
While still in the slow cooker, shred the meat with two forks and turn the heat to low and allow to cook for 1 more hour.