Bring a large pot of lightly salted water to a boil. Add pasta, and cook for 8 to 10 minutes or until al dente. Drain, and set aside.
Simmer water, chicken, diced onions, celery, minced parsley, bay leaf, salt and pepper in Dutch oven until chicken is tender. Remove bay leaf; discard. Remove chicken; cool.
Add potatoes, green onions, bouillon cubes, seasoned salt and poultry seasoning to broth. Simmer 15 minutes. Add milk, cooked pasta, and chicken; return to simmer.
Melt butter or margarine over medium heat. Add flour, stirring constantly, until mixture begins to brown. Add to soup; blend well. Let soup stand 20 minutes to blend flavors. Season to taste. Garnish with nutmeg and chopped parsley.