In a large, heavy Dutch oven, heat oil over high heat until it almost begins to smoke. Add flour and stir well to make a roux. Cook, stirring constantly until roux is a nutty brown color, then lower heat.
Add onions, celery, and peppers. Cook in roux for five minutes, until onions begin to brown.
Add chicken stock, garlic, bay leaves, and thyme. Simmer 15-20 minutes.
Cut chicken meat and andouille into bite-size pieces and add to pot. Simmer another 20 minutes.
Add hot sauce and green onions, and adjust seasonings with salt and pepper as needed. File can be added in the kitchen, or dusted lightly on the gumbo at the table. Serve with boiled long-grain rice.
