Pat the steak pieces dry with paper towels and season all over with salt and pepper.
Heat the olive oil in a large skillet over medium-high heat. Add the steak and sear until well-browned, about 3-4 minutes per side. Transfer the seared steak to the basin of a 6-quart or larger slow cooker.
Reduce the heat to medium. Add the sliced onion and bell peppers to the same skillet and cook, stirring occasionally, until softened, about 5-7 minutes.
Add the minced garlic and cook for 1 minute more until fragrant. Stir in the tomato paste and cook for 1 minute, stirring constantly.
Pour in the beef broth to deglaze the pan, using a wooden spoon to scrape up any browned bits from the bottom of the skillet. Bring to a simmer.
Pour the entire contents of the skillet over the steak in the slow cooker. Add the cumin, oregano, smoked paprika, and olive brine. Stir gently to combine.
Cover and cook on LOW for 7 to 8 hours or on HIGH for 4 to 5 hours, until the beef is very tender and shreds easily with a fork.
Remove the steak pieces to a large bowl or cutting board. Use two forks to shred the meat. Return the shredded beef to the slow cooker and stir in the halved olives. Let the mixture sit for about 10 minutes for the flavors to meld.
Serve the ropa vieja hot over rice, with black beans and lime wedges on the side.