Mama's Best Broiled Tomato Sandwich

Ingredients (9)

• + 2 tablespoons olive oil add to pantry
• + 2 tablespoons balsamic vinegar add to pantry
• + 4 ripe tomatoes, sliced add to pantry
• + 3 tablespoons mayonnaise add to pantry
• + ½ teaspoon dried parsley add to pantry
• + ¼ teaspoon dried oregano add to pantry
• + ¼ teaspoon black pepper add to pantry
• + 3 tablespoons grated Parmesan cheese, divided add to pantry
• ✓ 4 slices bread, lightly toasted