1. Preheat oven to 450°.
2. Place fish in a 13 x 9-inch baking dish coated with cooking spray. Drizzle with olive oil; sprinkle with 1/8 teaspoon salt and black pepper. Bake at 450° for 8 minutes or until desired degree of doneness.
3. Combine remaining 1/8 teaspoon salt, cucumber, and next 4 ingredients (through red pepper). Place one fillet on each of 4 bread slices; top with 1/4 cup sauce, 2 tablespoons watercress, and 1 bread slice.
Sustainable Choice: Wild Alaskan salmon is available for a few months. If unavailable, buy frozen Alaskan salmon.