Season the chuck roast generously with salt and pepper on all sides.

Heat olive oil in a skillet over medium-high heat and sear the meat for 4-5 minutes on each side until golden-brown.

Transfer the seared roast to a slow cooker, layer with onion and garlic, then add beef broth and sprinkle chili powder and cumin.

Cover and cook on low for 7-8 hours or high for 4-5 hours until fork-tender.

Shred the beef with forks and mix it back with the juices, adding lime juice.

Warm tortillas, fill with shredded beef, and top with desired toppings.