Heat olive oil in a large pot over medium heat. Add sliced celery, carrots, diced onion, and red bell pepper. Sauté for about 5 minutes until the vegetables begin to soften.

Stir in minced garlic and cubed potatoes. Cook for an additional 2 minutes, allowing the garlic to become fragrant.

Place the chicken pieces into the pot. Pour in the canned diced tomatoes along with their juices. Mix well to combine all ingredients.

Add chopped parsley, dried oregano, red pepper flakes, salt, and black pepper to the pot. Stir to evenly distribute the seasonings.

Pour in water and chicken broth. Bring the mixture to a boil, then reduce the heat to low. Cover the pot partially and let it simmer for about 1 hour, or until the chicken is cooked through and tender.

Once the chicken is cooked, remove it from the pot and shred it using two forks. Return the shredded chicken to the pot, stirring it back into the soup.

In a separate pot, cook the ditalini pasta according to the package instructions until al dente. Drain and set aside.

Add the cooked pasta to the soup just before serving. Stir well to combine. Ladle the soup into bowls and enjoy!