Brush fish with oil and season with cumin, salt, and pepper. Grill in a preheated grill pan or on a gas or charcoal grill on the greased rack of a covered grill directly over medium heat for 4 to 6 minutes per 1/2-inch thickness or until fish flakes easily when tested with a fork, turning once.
Warm tortillas in the pan or on the grill rack. Serve fish in tortillas with sour cream, salsa, and toppers.
Roasted Tomato Salsa
Preheat oven to 450 degrees F. Line a shallow baking pan with foil. Place tomatoes and onion in the prepared pan. Drizzle with 1 tablespoon of the oil and sprinkle with salt; toss to coat. Roast for 20 to 30 minutes or until nicely browned. Cool slightly.
In a food processor place roasted vegetables and cilantro. Cover and process until smooth, gradually adding remaining oil with motor running. Add chipotle to taste. Makes 1 1/3 cups.