Combine 1/2 cup flour, 1/2 teaspoon cayenne, pepper and salt. Dust chicken in flour mixture. Saute chicken in oil until browned on all sides. Lower heat and add remaining flour, stir constantly for 20 minutes. Add onions, celery and bell pepper. Saute for 5 minutes. Add garlic, saute for 2 minutes. Transfer to large pot. Add stock, bring to a boil. Add andouille, thyme and bay leaves. Simmer for 20 minutes. Add parsley, remove from heat, add file powder and serve.