Preheat oven to 350 F. Line a pan with aluminum foil. Set aside.
Brush the chicken very lightly with a little olive oil.
To season the chicken, mix together Old Bay Seasoning, garlic powder, onion powder, and celery salt.
Sprinkle chicken generously with seasoning on top and bottom.
Place chicken on prepared pan and bake for 20-25 minutes. (You may need more or less time depending on the thickness of your chicken)
Once the chicken is done, let it cool and then dice it up into small chunks and place in a large bowl.
Add diced celery, diced onions, diced eggs, sweet relish, and dill weed to the large bowl. Stir to combine.
Next, stir in the mayonnaise a little at a time until your desired creaminess is reached.
Stir in parsley and black pepper
Taste and adjust the seasonings if needed. (see note)
Cover and refrigerate until chilled. (about 1 hour)
Stir before serving. Serve with crackers or on buttered croissants.