In a large stock pot or dutch oven place the whole chicken, onion, red peppers, celery, carrots, potatoes, fire roasted tomatoes with their juices. Add enough cold water to cover by 1 inch.
Bring to a boil over high heat.
Add parsley, garlic, 1 tablespoon of kosher salt and pepper to taste.
Reduce the heat to medium-low, cover partially with a lid.
Let it simmer for about 2 hours until the chicken is falling off the bone. Remove chicken and let it cool, for about 30 minutes or until cool enough to handle.
Taste the stock and season with salt and pepper to taste, if needed. Reduce heat to low and let the soup continue to simmer.
Remove all the meat from the chicken and shred the chicken into pieces. Discard the skin and bones.
Meanwhile, cook pasta in a medium pot according to package directions until tender. Drain. Do not add uncooked pasta to the soup or it will soak up too much liquid and make the soup thick and more like a stew. Drain well and set aside in a serving bowl.
Using a potato masher, mash the soup around a few times, letting some of the potatoes get a little smashed. About 3 to 4 mashes, not too much.
Add the shredded chicken to the pot. Taste, add more salt and pepper if needed. Serve garnished (heavily in our house) with grated parmesan or romano cheese.