In a large bowl, mix together ground chicken, egg, bread crumbs, onion powder, garlic powder, oregano, salt, and pepper until just combined. Do not overmix.
Heat 1 tablespoon olive oil in a large pot over medium heat. Add the diced yellow onion, carrots, and celery, and cook until tender, about 3 minutes. Stir in 1 teaspoon poultry seasoning and cook for 1 more minute.
Add 6 cups chicken broth and 2 cups water to the pot, and bring to a rolling boil.
Use a small spoon to scoop ½-inch bits of the chicken mixture directly into the boiling broth. The meatballs do not have to be rolled or round.
Once all the meatballs are added, add 1 cup small pasta. Let the soup simmer uncovered for 8 to 10 minutes or until the pasta is tender and the meatballs are cooked through.
Taste the soup and add salt and pepper as needed for seasoning.