01 -
Preheat oven to 375°F. Grease 9x13-inch baking dish.
02 -
Arrange onion slices in dish, slightly overlapping.
03 -
Mix cream, garlic powder, paprika, salt, and pepper.
04 -
Pour cream mixture over onions. Top with cheeses and butter pieces.
05 -
Cover with foil, bake 25 minutes. Uncover, bake 20-25 more minutes until golden.
06 -
Rest 5 minutes. Garnish with parsley if desired.