1. Preheat oven to 250°.
2. To prepare sauce, combine mayonnaise, cilantro, buttermilk, and chile in a small bowl.
3. To prepare tacos, place Cedar-Planked Salmon with Barbecue Spice Rub in a baking dish. Cover with foil. Wrap tortillas tightly in foil. Bake the fish and the tortillas at 250° for 15 minutes or until thoroughly heated.
4. Combine cabbage, onions, and juice; toss well.
5. Spread about 4 teaspoons sauce down the center of each tortilla. Top each tortilla with about 2 ounces Cedar-Planked Salmon with Barbecue Spice Rub, 1/2 cup cabbage mixture, and 2 tablespoons tomato; fold in half. Serve immediately.