Place the chicken tenders in a large pot and pour in the low-sodium chicken stock so the chicken is mostly covered.
Bring the stock to a gentle simmer over medium heat and poach the chicken for about 15 to 20 minutes, or until cooked through and no longer pink inside.
Remove the chicken from the stock and let it cool slightly, then shred using a stand mixer with the paddle attachment or by pulling apart with two forks; pat the shredded chicken dry with paper towels if needed.
In a medium bowl, combine the mayonnaise, finely minced celery, dry Ranch dressing mix, salt, and ground black pepper; stir until smooth and well blended.
Add the shredded chicken to the dressing and stir until the chicken is evenly coated.
Transfer the chicken salad to an airtight container and chill for a couple of hours to allow the flavors to meld before serving.
Serve the chicken salad on sandwiches or over a bed of lettuce.
