1. Sprinkle beef evenly with salt.
2. Cook beef, in batches, in hot oil in a Dutch oven over medium-high heat 5 to 7 minutes or until browned on all sides. Remove beef, reserving drippings in Dutch oven. Add 1 Tbsp. chili powder to Dutch oven; cook, stirring constantly, 1 minute. Stir in tomato paste, and cook, stirring constantly, 2 minutes. Add 2 cups beef broth, and stir, scraping bits from bottom of Dutch oven. Return beef to Dutch oven, and stir.
3. Place beef mixture in a 4 1/2-quart slow cooker. Add onion and next 4 ingredients. Cook on HIGH 4 hours or on LOW 6 hours or until beef is tender. Serve with warm tortillas and desired toppings.