Place the chicken breasts in a pot of shallow water. Bring to the boil, reduce heat and poach for approx 15-20 min depending on the size of the chicken. Cool the chicken in the fridge.
Meanwhile wash the lettuce and let dry. Cut the salmon into pieces and place in a large salad bowl. Cut cos lettuce into pieces, and rip the coral lettuce with hands, place in salad bowl. Finely slice celery and chicken, place in bowl.
Dressing: Mix all ingredients together and shake well in a jar or whisk in a bowl until well combined. Add salt and pepper to taste.