Mix together the chili powder, cumin, Arizona dreaming, paprika, and black pepper. Rub it all over the beef roast and place the roast in the slow cooker.
Pour the beef broth around the beef roast and mix in the tomato paste. Sprinkle in the jalapenos, onions, and garlic.
Turn the heat to low and cook for 8 hours.
About 30 minutes before serving shred the beef in the slow cooker and allow to cook for 20 more minutes.
When ready to eat place the beef in a tortilla and top with cheese, sour cream, and salsa.