Heat olive oil in a large pot over medium-high heat. Dab both sides of beef dry with paper towels.
Season beef with salt and pepper (about 1 tsp salt, 3/4 tsp pepper) and sear in pot until browned on both sides, about 3 minutes each side.
Transfer beef to a 6 or 7 quart slow cooker. Pour beef broth over roast.
Sprinkle chili powder, cumin, onion and garlic powder evenly over roast. Cover slow cooker and cook on low heat 8 hours (high heat cooking is not recommend here).
Remove roast from slow cooker, shred beef (remove fat) and return shredded beef to slow cooker (season with a little more salt if needed).
Add in lime juice, cover with lid and cook on low an additional 5 - 10 minutes while preparing toppings and tortillas.
Remove beef from slow cooker with tongs to remove juices when plating or drain in a colander.
Serve in warmed tortillas with desired toppings.
Recipe source: Cooking Classy
Tortillas and toppings not included in nutritional value.