Heat a large non-stick skillet over high heat. Sear the beef cubes on all 4 sides, about 60 seconds per side. Remove from the pan and place directly in a slow cooker.
Place the diced onion, red bell peppers, carrots, celery, worcestershire sauce, beef broth, diced tomatoes, green chilis, tomato paste in the slow cooker. Add in the spices (chili powder, cumin, paprika, onion powder, garlic powder, and salt).
Cook on low for 8-12 hours.
Stir in the lime juice before serving. Serve with toppings if desired.