Add the olive oil to a large dutch oven and cook over medium heat. Sauté the onion, bell pepper, carrots, and celery until all of the vegetables are soft, about 5 minutes. Add the garlic, and cook for another 2 minutes until soft and fragrant, being careful not to burn the garlic.
Add the chicken stock, water, chicken seasoning packages, garlic powder, parsley flakes, oregano, thyme, cayenne pepper, and cajun seasoning. Bring to a boil and add the chicken. Boil for 10 minutes until the chicken is done.
Remove the chicken and shred. Add the chicken back to the soup and bring the soup back to a boil. Add the juice from one lemon to the soup and slice the other lemon and add to the soup. Allow the soup to boil for about 10 minutes.
Lastly, add the Fortune Udon Noodles and cook for 3-4 minutes until done. Remove from the heat and serve in large bowls. Garnish with green onions.