Heat the oil in a heavy-bottomed Dutch oven or large pot over medium-high heat. Cook the sausage until browned on both sides and remove.
Sprinkle the flour over the oil, add 2 tablespoons of butter and cook over medium heat, stirring constantly, until brown, about 10 minutes.
Return the Dutch oven to low heat and melt the remaining 3 tablespoons butter. Add the onion, garlic, green pepper, and celery and cook for 10 minutes.
Add Worcestershire sauce, salt, and pepper, to taste and the 1/4 bunch parsley. Cook, while stirring frequently, for 10 minutes.
Add 4 cups chicken stock, whisking constantly. Add the sausage. Bring to a boil, then reduce the heat, cover, and simmer for 45 minutes.
Add tomatoes and okra. Cover and simmer for 1 hour.
Salt and pepper to taste.
Add the shrimp and cook for 3-4 minutes.
Just before serving, add the green onions and chopped parsley.
Serve with rice, if desired.