To make the roux: In a large cast-iron or other heavy skillet, heat the oil over medium heat.
Slowly add in the flour, stirring or whisking CONSTANTLY. Continue cooking and stirring until flour and oil are combined and start to turn a golden brown. (Be extremely careful not to burn the roux or to splash it onto yourself)
Once the roux is the desired color, add in half of the onion, bell pepper, and celery and continue to stir for about one minute. Then add the rest of the vegetables, including the okra and the garlic and continue to cook and stir for another minute or two.
Remove skillet from the heat and stir in the seasonings and hot sauce if desired.
Place a second stockpot or Dutch oven on the stove over medium heat and add the seafood stock. Bring to a boil.
Add the roux mixture, including the vegetables, by spoonfuls to the boiling stock, stirring well after each addition.
Once all the roux is incorporated into the stock, add the sausage and lower heat to simmer for 30 minutes, stirring occasionally.
Just before serving, add the shrimp to the pot and cook for 8-10 minutes or until the shrimp turn pink and are cooked through.
To serve, place 1/4 cup of cooked rice in the center of a bowl and spoon 1 cup of the gumbo over the top.
Be sure to serve with crispy baked French bread to sop up all the delicious juices.
Serve with OSA Gourmet Datil Pepper Hot Sauce on the side for those who want an extra kick of heat.