Start with a tablespoon or two of oil in the bottom of the pot and sauté your aromatics (onion, celery, garlic).
Add a little salt and pepper while sautéing.
Once the aromatics change from raw to smelling good, add your stock, veggies, and cooked chicken, and bring it to a boil.
Once the veggies are cooked, add the noodles and cook according to the package instructions.
Bring it down to a simmer and taste test, adjusting salt if needed.
Add herbs like oregano and thyme if desired.
Let it simmer for a bit, and then it's ready to serve.