Begin by trimming the meat. Remove as much visible fat as you would like and any connective tissue from the roast. Then cut into about 1 inch squares.
Combine broth, peppers with sauce, ACV, lime juice and spices in a bullet or blender and pulse until everything is incorporated.
Dice onion. Add onion and meat to slow-cooker. Pour chipotle sauce over meat. Cook for 4-6 hours on high or 6-8 hours on low.
Once meat is tender and cooked through, use two forks to pull and separate meat. When the meat is cooked thoroughly, it should be fairly easy to shred.
Serve immediately or keep warm in the Crockpot for several hours. You can serve the meat with or without the chipotle sauce. The sauce is very spicy so I usually keep only about ⅓ of it with the meat when storing.
Notes
Those requiring a strict paleo version of the recipe will want to make their own chipotles in adobo. You can find a fairly simple recipe here. Some canned varieties can be relatively low carb but most contain some sugar so consider that when meal planning, and read the label.