Preheat a large bottom pot to medium-high heat.
Add butter to pot and let melt. Add ham, white onion, peppers, Cajun seasoning, salt, brown sugar, onion powder, and minced garlic. Stir in flour and continue to cook while stirring until you achieve a dark brown color, a brown roux. Slowly whisk in 6 cups of fish stock, add slowly to help avoid lumps. Bring to a boil and use remaining 2 cups of stock to adjust for consistency. Remove from heat and add the crabmeat. Set aside for use.
In a saute pan, over medium-high heat, saute shrimp and sausage. Place shrimp and sausage over grits, if using, and top with crab gravy sauce.
*Cooks note: For home use it is more practical to use instant grits. Cook your grits first and do not be afraid to season to your liking. This is a main component to your dish.