In a small bowl, combine the chicken, taco seasoning, and ranch dressing. Toss to mix well.
Place the chicken mixture in the bottom of the jar, then layer the remaining ingredients in the order listed into the jar, packing in as much romaine as you need to create a tight pack. Cover the jar, and place it in the fridge for up to five days.
Notes
Make this vegetarian by swapping in chickpeas for the chicken.