Mix spices, garlic, Tabasco, lemon juice and 2 teaspoons oil in a large shallow dish. Add chicken and rub all over with spice mix. Cover and refrigerate 10 minutes.
Heat a large non-stick frying pan over a medium heat. Add chicken and cook for about 2-3 minutes on each side, or until browned and cooked through. Remove, cover with foil to keep warm.
Heat remaining 2 teaspoons oil in same frying pan. Add onion and capsicum. Cook, stirring, for 4-5 minutes or until lightly browned and just tender.
Heat tortillas as directed on packet.
Thickly slice chicken. Place tortillas on a serving board, top with onion, capsicum and chicken. Add lettuce, avocado, cheese and yoghurt. Fold in half to serve.

White corn tortillas are lower in sodium than flour tortillas. You will find them in the Mexican food section in supermarkets.