Combine the chopped romaine lettuce, napa cabbage, cucumber, and scallions in a large serving bowl. Ensure all vegetables are finely chopped for optimal texture.

In a blender or food processor, combine the fresh parsley, dill, chives, minced garlic, ripe avocado, lime juice, olive oil, and 30 ml of water.

Blend the dressing ingredients until smooth and creamy. Season with salt and black pepper to taste. Adjust lime juice or water if necessary.

Pour the creamy avocado-lime dressing over the chopped vegetables in the serving bowl.

Toss gently with tongs until all ingredients are thoroughly coated with the dressing. Serve immediately.