Prepare the Bread:

If the bread isn't stale, you can toast it in the oven. Preheat the oven to 350°F (175°C), spread the bread cubes on a baking sheet, and bake until they're lightly toasted, about 10-15 minutes.

Make the Vinaigrette:

In a small bowl, whisk together olive oil, red wine vinegar, minced garlic, salt, and pepper.

Combine the Salad:

In a large bowl, combine the toasted bread, tomatoes, cucumber, red onion, and basil. Drizzle the vinaigrette over the salad and toss everything together to coat well.

Let it Marinate:

Allow the salad to sit for about 30 minutes before serving so the bread can absorb the flavors and soften slightly.

Serve:

Toss the salad again before serving. Adjust the seasoning with more salt, pepper, or vinegar if needed.