Combine chili powder, onion powder, ground oregano, ground oregano, ground cumin, garlic powder, red pepper and oil and rub evenly on the steak. Cover steak with plastic wrap and marinate in the refrigerator for 30 -60 minutes.
Combine sour cream, green chilies, chili powder, cumin and garlic powder. Mix together well and let set in the refrigerator.
To make the tortilla shell, press 1 tortilla shell into a medium bowl. Microwave for 1 1/2 to 2 minutes or until crisp. Repeat with other tortillas shells.
Preheat the grill and place marinated steak on the grill. Grill steak until desired doneness.
Place tortilla shell on a plate. Add shredded lettuce, cilantro, and red tomatoes. Place drained beans and corn on top of lettuce and tomatoes.
Slice steak across grain into thin strips. Place 4 oz. of steak on top of beans and corn. Place a dollop of sour cream on top.