Wash lettuce leaves and pat dry with a paper towel. Arrange on a platter.
Whisk together mayonnaise and ranch dressing in a small bowl.
Add shredded romaine lettuce to dressing and toss to coat evenly. Distribute shredded lettuce to each lettuce leaf.
Top each lettuce leaf with crumbled bacon, cherry tomatoes (sliced if larger in size), shaved parmesan cheese slices, diced green onion, salt and pepper.