In pan over medium heat, brown beef until cooked through; drain. Add black beans and corn. Stir in tomatoes with juices and half-and-half. Add onion powder, garlic powder, mesquite seasoning and pepper. Season with salt, to taste. Bring to simmer.
Add lime juice; stir. Sprinkle with cilantro.
Wash and chop lettuce. Place cheese and sour cream in bowls for toppings.
On plates, top crushed tortilla chips with meat sauce, lettuce, cheese and sour cream, as desired.