This is yet another way to cook gumbo. The use of butter instead of oil is usually the New Orleans or Creole way to make a roux.
Melt half the butter and saute the green onions, okra, white onions and crabs. In a separate pot put the shrimp, oysters, tomatoes and tomato juice with 1 1/2 quarts of shrimp stock and bring to a boil. Let boil for a minute, then add to the first pot. In a small skillet cook the other half of the butter and flour together until brown. Blend this brown roux with the File and some of the gumbo liquid to make a slurry and add to the gumbo. Add salt and pepper and cayenne to taste. Do not bring to a boil. Simmer for 1 1/2 hours.
To serve, pour 1 1/2 cups of gumbo into wide, flat bowls, then add 1/2 cup rice mounded up in the middle of the bowl of gumbo.