To a large skillet, add the olive oil, chicken, evenly sprinkle with 1 heaping tablespoon taco seasoning, and cook over medium-high heat for about 5 minutes, flipping intermittently so all sides cook evenly. Cooking time will vary based on thickness of chicken breasts and sizes of pieces. Allow chicken to rest in pan off the heat while you assemble the salad. To a large platter, add the lettuce, and evenly sprinkle with the tomatoes, corn, black beans, avocado, cheese, tortilla chips, and chicken; set aside. To a small bowl, add the mayo, sour cream, lime juice, 1 heaping tablespoon taco seasoning, and whisk to combine. Add the cilantro and stir to incorporate. Add additional lime juice to thin out dressing if desired. Taste dressing and depending on how much lime juice was used, add sugar to taste. Evenly drizzle dressing over salad. Extra dressing will keep airtight for up to 5 days in the fridge and makes a great veggie dip.