Spreading out the chips means even coverage with toppings.
Position a rack in the center of the oven and preheat to 350˚F. Coat a large baking sheet with cooking spray.
If using carnitas, combine the pork with the salsa verde until evenly coated.
Arrange half of the tortilla chips on the prepared baking sheet. Sprinkle with half of the cheese, the beef, and the beans. Repeat with the remaining chips, cheese, beef and beans.
Bake 10 minutes, until the cheese is melted and the nachos are heated through. As soon as the nachos are done, scatter on top the avocado, tomatoes, cilantro, jalapeno, salsa, and, if using, sour cream. Serve hot.