Several of my books have mentioned Courtbouillon. Here is the recipe. Enjoy

Now for the fish stock you can take the fish bones of the carcass and boil down with various spices. I also will take the shrimp peelings and boil that down to make a stock and freeze so that I have stock readily available.

Another great stock is when you have boiled crabs to make a stock from the shells (after enjoying your boiled crab). This gives you a heavily seasoned stock. Also works well with boiled crawfish.

3 pounds catfish (or red snapper, redfish, etc)
1/2 cup oil
2 onions, minced
1 clove garlic, minced
1 bell pepper, chopped
Couple of dashes of Worcestershire sauce
Couple of dashes tabasco sauce
1 can tomato sauce
Lemon slices

Heat oil

Mix spices with tomato sauce.

Add alternate layers of fish, lemon slices and tomato sauce

Cover and simmer for one hour. If more gravy is needed water or fish stock can be added.

Serve over rice.