In a small bowl, combine Mexican dressing and yoghurt. Season with salt and set aside.
Prep onion. Pat chicken dry and slice into1cm thick strips. Toss in a medium bowl with Mexican blend, tomato paste and salt.
Heat oil in a large fry-pan on medium heat. Cook chicken without stirring for 2 minutes. Add onion and corn and cook for a further3-4 minutes, stirring occasionally.
Remove pan from heat, add 2 tablespoons of dressing and toss to coat. Season with salt and pepper and rest, covered.
Prep avocado, capsicum, onion and beans. Toss all salsa ingredients together in a medium bowl with remaining dressing.
Serve lettuce with chicken and resting juices. Top with salsa.