Season roast with salt and pepper to taste.
Heat 2 tablespoons of olive oil in a large skillet over high heat until hot. Add beef cubes; sear for 3 minutes per side then transfer to a large crock cooker.
In a medium bowl, combine next 7 ingredients (garlic through chicken broth); pour mixture over the beef in the slow cooker.
Cover and cook on LOW for 5 to 8 hours or until beef is fork-tender and light pink in the center. Let cool for 15 minutes shred with 2 forks.