Etouffee and gumbo both have the trinity (onion, celery, and bell pepper) and a dark brown roux. The difference between etouffee and gumbo is that etouffee is thicker, made with butter roux, the roux should be peanut butter brown and has a gravy consistency. Gumbo is thinner, made with an oil roux, the roux should be cocoa brown and a soup consistency.