Dice the bacon and cook in a skillet over medium-high heat until crisp. Drain on paper towel. Set aside.
Combine the romaine and watercress and place onto a large serving platter.
Arrange the eggs, tomatoes, chicken, avocados and blue cheese in strips on top of the greens. (see photo)
Drizzle with some of the vinaigrette dressing. Serve immediately. Place remaining dressing at the table.
Dressing:
In small bowl, whisk vinegar, garlic and mustard. Add salt and pepper.
While whisking, slowly drizzle in olive oil until well combined.