In a large nonstick skillet (fry pan) saute onion and garlic in butter until tender. Stir in flour until blended. Gradually whisk in half-and-half until blended. Bring to a boil over medium-low heat; cook and stir for 2 mintues or until slightly thickened.
Add the cream cheese, salt, nutmeg, bacon and pepper, stirring until cream cheese is melted. Stir in spinach and 1/4 cup Parmesan cheese; heat through. Sprinkle with remaining Parmesan cheese.