Wash and spin lettuce, lay out between two paper towels or clean tea towels, roll up loosely & refrigerate until needed.
Slice and chop chicken into roughly 1 cm cubes.
Thinly slice celery sticks lengthwise and then cut into 5mm cubes.
Roughly chop cashew nuts.
In a medium bowl combine chicken, celery, nuts.
Add Green Goddess Dressing gradually until you are happy with the consistency (see notes).
Adjust seasoning with salt and pepper.
Slice croissants lengthwise but not all the way through. You're creating a pocket for the chicken salad, so you can try and leave the very tips of the croissant uncut.
Use an ice cream scoop to add the chicken salad, spread it out and gently pack it in with a spatula or spoon.
Then tuck in pickled red onions and lettuce.