Combine mashed avocado, 1 tablespoon lime juice, sour cream, and salt. Cover avocado mixture, and chill.
Combine remaining 1 tablespoon lime juice, shredded chicken, and next 3 ingredients in a bowl, and toss gently.
Preheat oven to 42
Divide tortilla chips among 3 individual ovenproof plates on a large baking sheet. Top each plate with 2/3 cup chicken mixture and 1/4 cup shredded cheese.
Bake nachos at 425 for 6 minutes or until cheese melts. Top each serving with 2 tablespoons avocado cream.
Serve immediately.
Note: If you prefer, microwave individual servings at HIGH 3 minutes or until cheese melts.