Melt butter in pan over medium-low heat. Sauté asparagus and bacon in the LID HALF of the pan or in a separate pan until asparagus is crisp-tender and bacon is crisp. Pour egg mixture into HANDLE HALF of pan. Cook 2 minutes, until eggs begin to set up. Close lid to combine asparagus and bacon with egg. Cook 2 minutes. Using a hot pad, hold handles together and flip pan 180 degrees to cook on the other side. Open and sprinkle with cheese. Close pan; cook until golden brown.