Poach chicken: In a large pot, arrange the chicken breasts in a single layer.

If using, place lemon slices and dill sprigs on chicken.

Pour water over the chicken breasts, covering by at least an inch.

Bring water to a boil, then reduce to simmer and cook for 10 or until the center of the chicken reaches 165° with an instant read thermometer.

If you don’t have a thermometer, check that the thickest part of the chicken is opaque.

Slice chicken into bite-sized pieces.

In a large bowl, combine chicken, apple, onion and celery.

In a medium bowl, combine mayonnaise and lemon juice and season with salt and pepper.

Whisk until combined.

Pour dressing over chicken mixture and toss.

Garnish with dill and serve.