Gumbo, like all great folk recipes, is open to plenty of individual interpretation. Recipes may include seafood, poultry, or small game as well as sausage and some form of smoked pork. What's crucial to any true gumbo, however, is what's known as the Creole/Cajun holy trinity of onion, bell pepper, and celery. Gumbos also call for a thickener, which generally shows up in the form of okra or filé (pronounced fee-LAY, this consists of ground dried sassafras leaves). But we still haven't gotten to the most important ingredient, a dark brown roux, which many believe to be at the heart of good gumbo.
A recipe for great gumbo that featured a thick, smooth, completely unified sauce, with lots of well-seasoned vegetables, meat, and fish.
For a deep, dark roux in half the time, heat the oil before adding the flour. Add the roux to room-temperature fish stock (made from shrimp and clam juice) to prevent separating. Use plenty of garlic, dried thyme, and bay leaves but just 1/4 teaspoon of cayenne pepper. Add generous amounts of smoked sausage and shrimp, and finish with parsley and scallions.