Preheat the oven to 450°F. Spray 18 muffin cups with butter flavored cooking spray. Set aside. In a medium mixing bowl, beat the egg whites, then add the shredded hash browns, Parmesan cheese, garlic salt, onion powder and black pepper. Mix until well combined.
Divide evenly among 18 muffin cups. Press the potato mixture firmly onto the bottom and up the sides of each muffin cup.
Spray the tops of each nest with butter flavored cooking spray.
Bake for 22-25 minutes or until golden. Allow to cool for 5 minutes before removing from the pan. Run a knife or off set spatula gently around each to loosen the edges.
Fill with shredded cheese, warm pulled pork barbecue, bacon crumbles, sour cream and snipped fresh chives.