This open face tomato and cheese sandwich is broiled in the oven and has so much flavor.
Preheat your oven to broil.
Lightly toast the 4 slices of bread.
In a small bowl, combine the olive oil and vinegar. Add the tomato slices, allowing them to marinate in the mixture. Stir occasionally.
In a separate small bowl, mix together mayonnaise, basil, oregano, black pepper and 6 teaspoons parmesan cheese.
Generously spread the cheese mixture on each of slice of toasted bread, dividing it evenly between the 4 slices. Top with the marinated tomato slices, allowing the excess marinade to dip of before putting the tomatoes on the bread. Add a few slices of red onion.
Place the bread on a foil lined baking sheet and broil until the cheese is bubbly and melted, approximately 5 minutes.
Remove from oven, and sprinkle with green onion.