Season the chuck roast generously with cumin, chili powder, smoked paprika, salt, and pepper.

Heat a cast iron skillet or stainless steel pan over medium-high heat until it’s hot. Place the seasoned beef in the hot, dry skillet and sear it for about 3-4 minutes per side, or until it’s nicely browned. Let the beef sit without moving it to ensure a good sear.

Note: If you prefer, you can use oil in the skillet to help with the searing process.

Transfer the seared beef to the slow cooker. Add the chopped onion, garlic, beef broth, and lime juice.

Cover and cook on low for 7-8 hours, until the beef is fork-tender and shreds easily.

Remove the beef from the slow cooker and shred it with two forks. Return the shredded beef back to the juices in the slow cooker.

Serve the shredded beef in tacos, on rice, in sandwiches, or however you like.