Place the flour into a bowl. Smooth out all lumps with a knife. Over medium-high heat, pour the oil into a Dutch oven. Allow the oil to come up to heat. Sprinkle the flour into the oil - while whisking constantly with a wire whip. For the roux to achieve a dark chocolate brown color, it will take about 6-8 minutes of whisking.
Saute the onion in the roux with a little salt. Break the roux down with water and wine. Whisk to combine the roux and the liquids. Pour in the tomato puree, worcestershire and hot sauce. Season to taste with salt. Bring the liquids to a boil, cover then cut the heat to a slow simmer for 30 minutes.
Sprinkle the shrimp with a self-determined amount of the above spice blend.
Increase the heat on the pan until the liquid boils. Throw in the shrimp. When the liquids come back to a boil, stir, shut off the heat and clamp the lid. Allow the dish to rest for 8-10 minutes. Serve over rice.