Season the flank steak with salt and black pepper.
Preheat a grill or grill pan over medium-high heat.
Brush the grill with olive oil and add the steak.
Grill for about 4-5 minutes per side for medium-rare, or until desired doneness.
Remove from the grill and let it rest for 5 minutes before slicing.
While the steak is resting, preheat the oven to 400°F.
Spread the bread cubes on a baking sheet and drizzle with olive oil.
Toss to coat and bake for about 10-12 minutes, or until golden and crispy.
In a large bowl, combine the cherry tomatoes, cucumber, red onion, and basil.
In a small bowl, whisk together the red wine vinegar, Dijon mustard, and extra virgin olive oil.
Pour the dressing over the salad and toss to combine.
Add the toasted bread cubes to the salad and toss gently.
Slice the grilled steak against the grain and serve on top of the salad.