Saute the celery and carrots in the olive oil over medium heat for about 7 minutes. Once softened, add the shredded chicken and chicken broth.
Bring to a boil, then reduce to a simmer and cook for about 15 minutes. Add the garlic powder, and salt and pepper to taste.
You can either add your pasta to the pot, or just put some in each bowl and spoon the soup over it. If you put all the pasta in and have a lot of soup left over, it does tend to soak up all the broth, so I usually keep them separate until serving.
Notes
You can use gluten free pasta or regular pasta, or you can even use cooked rice.