If making the dressing, combine all the vinaigrette ingredients and refrigerate the jar for up to one week or, until ready to use
Make the blackened chicken:
On a flat surface, pat dry the chicken breasts. Distribute the seasoning on both sides of the chicken breasts.
Heat a cast iron skillet over medium-high heat. Once hot, melt the butter. Place the chicken breasts on the pan and cook the first side for 7 minutes. Flip the chicken breasts over and cook for another 7 minutes on the other side until the internal temperature reaches 165F. Cooking time on the second side will vary by the thickness of the chicken breast.
Remove the chicken breasts from the pan onto a board to rest for 5 minutes before slicing.
Build your dream salad:
Assemble the salad in a large bowl by layering the chopped Romaine, topping it with the hard-boiled eggs, cherry tomatoes, sliced cucumbers, avocado slices, sliced shallot, blue cheese crumbles, crumbled bacon, and sliced chicken breasts.
Drizzle ½ cup salad dressing over the salad and toss to combine. Add more salad dressing if desired.
For Meal Prep:
Layer all the salad ingredients inside 4 meal prep containers except for the sliced avocado. Pack about 2 tablespoons of salad dressing inside four small, lidded containers. The morning of, slice ¼ of an avocado and pack it inside the lunch container. Drizzle salad dressing right before your first bite.