Finely dice the celery, onion, carrots, potato, and bell pepper into small pieces, about ¼ to ½ inch in size.
Heat a Dutch oven over medium-high heat and add a drizzle of olive oil.
Once the oil is hot, toss in the diced celery, carrots, potato, onion, and bell pepper. Sauté for about 5 minutes, stirring occasionally, until the vegetables begin to soften.
Stir in the tomatoes, parsley, oregano, garlic, and red pepper flakes, ensuring the ingredients are well combined.
Pour in the water and broth, then cover the pot and bring the mixture to a boil over medium-low heat.
Partially cover the pot and reduce the heat to a simmer, allowing the soup to cook for 1 hour. Use a potato masher to lightly mash some of the vegetables in the bottom of the pot for a thicker texture.
Add the chicken to the soup and continue to simmer for an additional 30 minutes until the chicken is fully cooked and tender.
While the chicken is simmering, cook the pasta in a separate pot according to the package instructions. Drain and set aside.
Just before serving, stir the cooked pasta into the soup. Serve hot and garnish with freshly grated Parmesan cheese. Enjoy!
