Mardi Gras Gumbo recipe

1/4 cup vegetable oil
1/4 cup all-purpose flour
2 quarts (8 cups) water
1 pound shrimp, cleaned and deveined
1 chicken, cut up
1 large onion, chopped
2 teaspoons salt
1 clove garlic, chopped
1/4 teaspoon cayenne pepper
1 jar fresh oysters (1 pint)
Tabasco sauce (optional)
Gumbo file

Slowly brown oil and flour to make dark roux. Add onions, simmer until onion wilts. Add salt, garlic, and water. Bring to boil. Add cayenne pepper, chicken (which has been browned in separate pot) with all contents of browning pot. Simmer 30 minutes. Add shrimp. Simmer 20 minutes. Add oysters. Simmer 20 or 30 minutes more.