Watch your roux
Most gumbo recipes begin with roux, and for good reason: it's the foundation for the entire dish. Roux is flour that's browned in fat (like oil or butter) to thicken and flavor gumbo and other Cajun dishes. Although it's just two ingredients, the color of a roux is fiercely debated among gumbo aficionados. Many say a proper gumbo roux should be chocolate brown, for the richest flavor. Our Test Kitchen prefers butter over oil for the rich, nutty flavor. But butter burns easily, making a lighter golden brown roux. But Leah Chase, the chef behind New Orleans' legendary restaurant Dooky Chase, is not a fan of butter in gumbo. She uses neutral oil in her gumbo roux because it has a higher smoke point, which means you can cook it darker. Whatever color you prefer, you'll need a heavy-bottomed pan (cast iron is best) and a whisk for constant stirring. Keep a close eye on it—once you see black specks, it's burned and you will need to start over.
Go low and slow
Gumbo is a project. And you can't rush it. A really great gumbo takes the better part of a day to make, from prepping the ingredients, to making a roux, to simmering everything low and slow. Slow cooking allows all of the flavors to marry together and keeps the gumbo from burning or over-reducing. Some people say that gumbo tastes better the longer it sits, and even recommend making it a day in advance.
Finish with filé
Gumbo is traditionally served over steamed white rice (and sometimes potato salad!), with sliced scallions and hot sauce on the side. But there's another important finishing touch: Filé ("FEE-lay"😉 powder, which is made from sassafras leaves. It is typically sprinkled on individual servings to thicken and season gumbo. While you can certainly make gumbo without it, we like the spice's earthy, slightly floral flavor. If you can't find filé powder at a supermarket or gourmet store, order it online dagnabit. Go on now, git!