A dozen oysters shucked (leave oysters attached to the bottom shell).
Put a dollop of garlic butter (adjusting for oyster size) on each oyster.
Commercial garlic butter is fine but it’s also easy enough to make from scratch.
Sprinkle shredded parmesan cheese on top of each oyster. Again the amount will be determined by the size of each oyster.
Cover each entirely.
Bake in the oven at 425 degrees until golden brown and the cheese is melted.