Preheat oven to 350°.
To prepare vinaigrette, combine first 7 ingredients in a small bowl; stir with a whisk.
To prepare salad, arrange bread cubes in a single layer on a baking sheet. Lightly coat bread cubes with cooking spray. Bake at 350° for 18 minutes or until toasted. Combine bread, tomato, onion, basil, pecorino Romano cheese, and 1/4 teaspoon pepper in a large bowl. Drizzle vinaigrette over bread cube mixture; toss gently to coat. Sprinkle beef with 1/4 teaspoon salt. Place beef on grill rack coated with cooking spray; grill 3 minutes on each side or until beef is medium-rare or desired degree of doneness. Serve beef over salad.