Remove the edible meat from the chicken carcass, reserving the skin, bones and cartilage for the broth.
Put the edible portion in the fridge until you are ready to use it.
Place the carcass in an 7 quart stock pot and fill it with water, leaving about a 1/2 an inch space from the top to keep it from boiling over too much.
Add the herbs and spices, and bring to a boil over high heat.
Continue to boil for approximately 2 hours, uncovered. The broth will be boiled down about a quarter of the way when it's finished. You will see the that the water has taken on a dark color. That's your broth!
Place a fine-meshed sieve over another large pot and strain the broth through it. Make sure the strainer is as finely meshed as possible because this process will also remove the carby parts of the garlic powder and herbs leaving you with just a flavored broth. If you can't get it all out, simply let the broth cool and then try again. Most of the seasoning will rise to the top where it's easy to skim off the top.
Use this broth to make your soup. (See below)
Using the entire batch of broth you made, bring it to a boil and toss in the celery and half the fresh parsley.
Let it boil for about 20 minutes, and then toss in the chicken just to warm it up for about another 10 minutes or so. It's done when the celery is soft and the chicken is warmed through.
When serving, top with the remainder of the fresh parsley to your liking.
Add salt to taste as needed.