Leftover steak adds substance to classic Italian bread salad. Toss vegetables with vinaigrette, and let stand at room temperature to draw out flavorful juices. With bread, vegetables, and meat, this dish doesn't need any accompaniments other than a glass of wine (try pinot noir).
Arrange bread cubes in a single layer on a baking sheet. Bake at 400° for 8 minutes or until toasted; cool.
Combine tomato and next 6 ingredients (through garlic) in a large bowl. Combine vinegar, oil, sugar, black pepper, and salt. Add vinegar mixture to tomato mixture; toss well. Cover and let stand 1 hour.
Add bread cubes, arugula, and Garlic-Rubbed Flank Steak to tomato mixture; toss gently to coat. Serve immediately.