Brush bread with olive oil and grill or toast in a pre-heated 400 degree oven until golden brown.
Meanwhile, combine tomatoes with salt and set aside for 10 minutes.
Add the olive oil, oregano, onions & garlic and mix thoroughly. Taste and adjust seasoning if needed.
Rub the toasted bread with the whole garlic. Top the bread slices with tomato salad and top with parmesan cheese.
Serve immediately after adding the topping so the bread doesn't get soggy.