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.
30 minutes before finishing, remove 1/2 cup of the liquids from the chili and place it into a small bowl. Whisk in 2 tablespoons cornstarch until smooth. Pour back into the slow cooker and stir to combine. Let continue cooking 30 minutes as the cornstarch slurry causes the juices to thicken.
Stir in the lime juice before serving. Serve with toppings if desired.