Put the chicken breasts, chopped onion, minced garlic, sliced carrots, and celery in your crockpot.
Add the poultry seasoning and bay leaf — season with salt and freshly ground pepper.
Pour in 8 cups of the chicken broth and cook on low for 6 hours or till the chicken is tender.
Remove chicken breasts. Shred the chicken breasts, return them to the crockpot, and add at least 8 ounces of egg noodles. Add the whole 12-ounce bag if you like a lot of noodles and/or have the space. You may need an additional 2 cups of chicken broth. Noodles should be covered with liquid. Add extra broth accordingly.
Cook on low for another 30 minutes or until noodles are cooked but not too soft.