Preheat oven to 350 degrees. Lightly oil 12 cup muffin tin. In large bowl, combine the cornmeal, salt and baking powder. Stir in the bacon fat. Add eggs and buttermilk and blend well. Stir in the onion. Fill each muffin cup with 2 tablespoons batter. Cover with 2 tablespoons of pulled pork and top with an additional tablespoon of batter and cheese. Bake for 35 minutes or until muffins are fully cooked. Allow the muffins to cool and remove from the cups. Serve with additional salsa.