In a large Dutch oven saute okra in 2 tbsp vegetable oil. over medium heat, until golden brown, about 15 minutes. Add onions and celery and cook until wilted.
Add 4 cups of water and simmer for 15 minutes.
In a large frying pan, heating remaining 3 tbsp of vegetable oil over medium low heat, and add chicken to saute, until it turns brown, about 5 minutes on each side.
Tranfer the cooked chicken to the okra mixture. Meanwhile, stir flour in pan and cook, stirring until nut brown roux begins to develop, about 20 minutes. Remove from heat and stir into mixture water from the okra mixture. Stir this mixture back into the Dutch oven.
Bring the entire dutch oven to boil and add salt, black pepper, and cayenne, and then bring to a simmer. Cook for 50 minutes.
Just before serving, add scallions and parsley for garnish and serve over rice, with French Bread.