Spray the bottom and sides of 6-quart slow-cooker crock with non-stick cooking spray. Generously season the beef with salt and pepper on all sides and place in slow cooker crock. Add all remaining ingredients, cover, and cook on low for 8 hours.
When done cooking, remove the lid and shred beef with two forks while still inside the slow cooker.
Allow shredded beef to marinate in warm cooking juices for 5 minutes to absorb more flavor. Transfer shredded beef from slow cooker to a serving platter with tongs, allowing excess liquid to drain.
Top with chopped cilantro and serve immediately with fresh lime wedges and additional cooking juices on the side, if desired.
Enjoy!