First rub the fish with a generous amount of a spice mix made with regular chile powder, chipotle chile powder (or cayenne pepper), ground coriander, and ground cumin. Sprinkle it on the fish ...
Here's what it was like to try Garten's recipe at home ... a teaspoon each of garlic powder, chipotle-chile powder, and crushed red pepper flakes, and 1½ tablespoons of olive oil.