In a mixing bowl, combine quartered cherry tomatoes with chiffonade-cut basil, ½ tablespoon of olive oil, dried oregano, and mozzarella pearls. Gently toss to ensure even coating. Set aside.

Preheat the grill to medium-high, around 375°F, ensuring the grates are clean and oiled.

Grill the seasoned steak for about 4–6 minutes per side until desired doneness. Let it rest for 5 minutes.

Slice rustic bread into ¾”-1” thick pieces. Brush with olive oil and grill oil-side down for 1–2 minutes until golden brown.

Assemble the crostini by topping each slice of grilled bread with the tomato mixture and cubed steak. Season with salt and pepper to taste.

Sprinkle chopped parsley over each crostini before serving for garnish.