In a small bowl, whisk together the ingredients for the marinade. Add the chicken breast to the marinade and toss to coat evenly. Cover and let the chicken marinate in the fridge for at least 30 minutes. (or overnight if time permits)
Add one tablespoon of cooking oil to a large skillet over medium-high heat. Cook the chicken breast for 5-6 minutes on each side, or until golden brown and they reach an internal temperature of 160 degrees Fahrenheit.
Place the chicken on a plate and set it aside.
Prepare the Avocado Dressing.
Assemble the salad. Layer the chopped romaine, arugula, cilantro, black beans, sliced onions, diced avocado, and sweet corn in a large bowl. Slice the chicken into strips and place it on top of the salad.
Top the salad with Avocado Dressing (or your favorite dressing) and enjoy!