1. Combine mashed avocado, 1 tablespoon lime juice, sour cream, and salt. Cover avocado mixture, and chill.
2. Combine remaining 1 tablespoon lime juice, shredded chicken, and next 3 ingredients in a bowl, and toss gently.
3. Preheat oven to 425°.
4. 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.