Ingredients

• 4 teaspoons chili powder, preferably made with New Mexico or ancho chiles (see Note)

• 2 tablespoons lime juice

• 2 tablespoons extra-virgin olive oil

• 1 teaspoon ground cumin

• 1 teaspoon onion powder

• 1 teaspoon garlic powder

• 1 teaspoon salt

• ½ teaspoon freshly ground pepper

• 2 pounds mahi-mahi or Pacific halibut (see Note), 1/2-3/4 inch thick, skinned and cut into 4 portions

• ¼ cup reduced-fat sour cream

• ¼ cup low-fat mayonnaise

• 2 tablespoons chopped fresh cilantro

• 1 teaspoon lime zest

• 2 tablespoons lime juice

• 1 teaspoon sugar

• ⅛ teaspoon salt

• Freshly ground pepper

• 3 cups finely shredded red or green cabbage

• 12 medium corn tortillas, warmed (see Tip)