Heat the oil in a skillet or cast iron over medium heat. You may add more oil as you cook. Add bread cubes, let it sit for a minute, then toss frequently. If bread is browning too fast, adjust heat Continue browning for about 8-10 minutes, or until nicely browned. Or preheat oven to 425 degrees F. Spread out bread cubes on a parchment-lined baking sheet.
Drizzle about 1-2 tablespoons oil and a pinch of salt over the bread cubes.
Then bake in a preheated oven for about 7-10 minutes until dried out and pale golden brown at the edges.
Remove from the oven and let it cool on a wire rack.
In a small mixing bowl, combine tomatoes, onions, bread cubes, cucumber, mozzarella, and olives
In a medium bowl, combine remaining, garlic, vinegar, Dijon mustard salt, and black pepper to taste. Add olive oil until the mixture is thickened. Stir in thyme and oregano.
Pour dressing over the bowl of tomatoes.
Toss to fully combine, adjust seasoning to taste. Top with capers and basil before serving, if desired.