Add 3-4 cups of browned flour evenly to a baking sheet.
Bake for one hour, mixing the flour every 15 minutes to bake evenly.
Once the flour is browned, sift and add to an airtight container and store in fridge for up to 6 months.
Add 2 Tbsp olive oil and the onions, celery, bell peppers, and garlic to pot. Heat on medium heat until vegetables are a dark brown color. Add small amounts of water as necessary to keep it from burning to the bottom of the pot.
Add the shrimp to the pot and cook until fully pink.
Add the water, seafood stock, crab meat, and seasonings. Cook for one hour.
Mix 1/2 cup of browned flour and 1 cup of water to make a pour-able paste. Add to the gumbo and cook another 30 minutes.