First, in a large, heavy pot or Dutch oven, mix your flour and oil until smooth.
Then cook it over medium-high heat for 5 minutes, stirring constantly with a large wooden spoon.
After that, reduce your heat to medium and cook, stirring constantly for another 15 minutes or until your roux is a dark reddish brown.
Now that your roux is ready, add in your chopped onion, celery, garlic, black pepper and red pepper.
Mix well and cook over medium heat, stirring often, for 3 to 5 minutes until your veggies are crisp-tender.
Now, slowly stir in HOT chicken broth, sausage, and okra. Then, bring it all to a boil.
Once it begins to boil, reduce the heat so that your gumbo is at a steady simmer and cover your pot. Simmer for 20 to 30 minutes.
Finally, add your raw shrimp to your cooked gumbo and simmer for an additional 5 to 10 minutes or until your shrimp is just cooked. You don’t want to add shrimp any sooner because it will get overcooked and mushy.
Now, remove gumbo from heat and mix in your filé powder.
Serve over top of white rice and garnish with sliced spring onions.