Place a soup pot over medium heat and coat with the oil. Add the onion, garlic, carrots, celery, thyme and bay leaf. Cook and stir for about 6 minutes, until the vegetables are softened but not browned. Pour in the chicken stock and bring the liquid to a boil. Add the noodles and simmer for 5 minutes until tender. Fold in the chicken, and continue to simmer for another couple of minutes to heat through; season with salt and pepper. Sprinkle with chopped parsley before serving.