Rinse Romaine lettuce leaves under cold water and pat thoroughly dry with paper towels.

In a medium mixing bowl, combine the shredded chicken, crumbled bacon, and ranch dressing.

Add the shredded cheddar cheese and diced red onion to the chicken mixture and stir until well incorporated.

Place the lettuce leaves on a clean work surface or serving platter.

Distribute the chicken mixture evenly among the 8 lettuce leaves, placing approximately 1/4 cup of filling into each boat.

Top each boat with diced tomatoes and minced chives.

Serve immediately or refrigerate for up to 2 hours before serving.