Season the chicken. Pat the chicken dry. Rub it with 1 tablespoon of olive oil, ½ teaspoon of salt, and the black pepper.
Cook the chicken. Heat a grill or grill pan over medium heat. Cook the chicken for about 5 minutes per side, or until the center reaches 165°F (74°C). Transfer it to a plate and let it rest for 5 minutes before slicing.
Make the dressing. In a small bowl, whisk together the remaining 1 tablespoon of olive oil, lime juice, honey, and remaining ¼ teaspoon of salt.
Prepare the salad base. Add the romaine, corn, tomatoes, cucumber, and red onion to a large serving bowl. Pour over about half the dressing and toss gently.
Finish and serve. Arrange the sliced chicken and diced avocado over the salad. Drizzle with the remaining dressing, scatter the cilantro on top, and serve right away.
For a meal-prep-friendly salad, keep the dressing, chicken, and chopped vegetables separate until serving. Add the avocado just before eating to help it stay fresh. To save time, use leftover grilled chicken or ready-cooked corn.