Place chicken in a large pot or Dutch oven
Add water or chicken broth to cover the chicken
Add salt, black pepper, onion, celery, and garlic if desired
Bring to a boil over medium-high heat
Reduce heat to low and simmer until the chicken is fully cooked
Cook bone-in chicken for about 30 to 45 minutes
Cook boneless chicken breasts for about 15 to 20 minutes
Remove the chicken from the pot
Let the chicken cool slightly
Shred or chop the chicken into bite-sized pieces
Return the chicken to the broth or set it aside until ready to add
Taste and adjust seasoning before adding dumplings