In a blender or food processor, combine all the dressing ingredients and blend until smooth and creamy. Refrigerate leftovers up to 1 week.
Cook the chicken:
Heat oil inside a large pan over medium-high heat. Season chicken breasts with taco seasoning and cook the first side for 6 minutes and flip, cooking the other side for another 5 minutes, until the internal temperature has reached 165F. Remove from pan and set aside.
Pack it for lunch:
Divide the chopped lettuce between 6 lunch containers. Top with black beans and corn.
Cut the chicken breasts into 1-inch pieces and distribute them over the salad. Top with cherry tomatoes, shredded cheese, and avocado.
Pack the Jalapeño Ranch Dressing into mini sauce containers and send with the salads.