Cut chicken fillets in half through the side to make 4 thin steaks in total. Combine spice blend and oil in a large shallow dish. Add chicken steaks and turn to coat evenly with spice mixture.
Heat a large non-stick frying pan over a medium-high heat. Add chicken. Cook for about 3 minutes on each side or until evenly browned and cooked through.
Meanwhile, combine beans, tomato, onion, coriander and salsa in a small bowl.
Split rolls in half and toast lightly.
To serve, place lettuce over base of rolls, then top with chicken, bean mix, avocado and roll tops.