1. Preheat grill to medium-high.
2. Combine dressing and basil in a medium bowl. Remove 2 tablespoons of dressing mixture; spoon over fish. Grill fish 8 minutes or until opaque in center, turning after 4 minutes. Sprinkle with salt and pepper.
3. While fish cooks, add tomato and avocado to dressing mixture in bowl; toss well. Spoon mixture over grilled fish. Yield: 4 servings (serving size: 1 fish fillet and 1/3 cup tomato mixture).