Season the chicken breasts with salt and pepper and cook for about 6 minutes. Flip the chicken and cook the second side for about 6 minutes more, or until chicken is cooked through.
Allow chicken to rest for 5 minutes.
Roughly chop the chicken into bite-sized pieces.
Place the diced avocado and half of the freshly squeezed lime juice into a large mixing bowl. Use a fork to mash the avocado until it reaches a creamy consistency. Add the jalapeño, 1 tablespoon cilantro, ¼ teaspoon garlic powder, and ¼ teaspoon cumin. Season well with salt. Stir to combine. Mix in the cubed chicken.
Next prepare the Chimichurri Dressing. Add the oil, vinegar, remaining lime juice, chives, 1½ tablespoons cilantro, ¼ teaspoon cumin, ¼ teaspoon garlic powder, and crushed red pepper flakes to a mixing bowl. Season with salt, and whisk until well combined.
Assemble salads by arranging lettuce on serving plates. Add tomatoes, bell pepper, and corn. Drizzle the Chimichurri Dressing over the salads. Add heaping spoonfuls of the guacamole chicken, and top each salad with a few crushed tortilla chips. Serve.