Remove the core from the head of lettuce with a knife and gently remove 8-12 leaves (2-3 per person), keeping them whole. Rinse and wrap in paper towels then put into individual sized plastic storage bags or containers and store in the fridge until ready to pack into the lunch.
In a mixing bowl, toss the chicken with the remaining ingredients, mixing well. Divide the salad among 4 individual sized storage containers.
To eat, scoop some salad into the lettuce leaves and enjoy.