Mix the mayonnaise, mango chutney and lime rind together in a large bowl. Toss the lime juice with the avocados, then add to the dressing. Add the spring onions, cucumber and chicken and fold the mixture together lightly so that it is semi-mixed.
Divide the lettuce leaves between 4 serving plates and top with the other salad leaves. Spoon over the chicken salad and garnish with torn coriander leaves, if liked. Serve immediately.