In a large skillet, heat the olive oil over medium-high heat. Season the beef chunks with salt, black pepper, cumin, chili powder, garlic powder, and onion powder. Sear the beef on all sides until browned, about 5-7 minutes.
Transfer the seared beef to a slow cooker. Pour the beef broth and lime juice over the meat. Cover and cook on low for 8 hours or high for 4 hours until the beef is tender and easily shredded.
Once cooked, shred the beef using two forks and mix it with the cooking juices.
In a separate skillet, warm the corn tortillas over medium heat for about 30 seconds on each side until pliable.
To assemble the tacos, place a generous portion of shredded beef on each tortilla. Top with diced onion and chopped cilantro.
Serve with lime wedges on the side for squeezing over the tacos.