Pre-heat a grill to 180 degrees Celsius. Lightly toast the pita bread for about 2 minutes or until it's slightly crispy. Alternatively you could crisp it up in a sandwich press. Set aside.
In a small bowl, combine the tandoori paste and 100g of the yoghurt and mix to combine. Add the chicken pieces to the tandoori mixture and toss until well coated.
Place the chicken on a tray lined with baking paper and cook under the grill for 5 minutes or until the chicken is cooked through. Once cooked, slice the chicken into bite sized pieces.
Spread each pita pocket with tomato salsa and top with chicken, avocado, capsicum, onion, mushrooms and cheese. Grill for 5-8 minutes or until cheese has melted.
Top with a dollop of natural yoghurt and sprinkle with fresh coriander.