A breezy spring lunch, perfect with a bowl of soup!
Preheat the oven to the broil setting.
While the oven is heating up, whisk the olive oil and vinegar together in a shallow bowl. Marinate the sliced tomatoes in this mixture, giving them an occasional stir.
In a separate small bowl, combine the mayonnaise, parsley, oregano, black pepper with 4 teaspoons of the Parmesan cheese. Spread that mixture on each slice of toasted bread. Place the prepped tomato slices on 2 slices of bread and sprinkle each with the leftover Parmesan.
Place the bread slices on a baking sheet and broil them in the oven for 5 minutes. You're good when the cheese turns golden brown. Serve immediately, either open faced or closed.