In a bowl combine all the ingredients except the oysters, and mix well. Adjust the seasoning to taste and transfer the mixture to a large piece of plastic wrap.Roll up the flavored butter to form a tight log and freeze.(Alternately, the flavored butter can be stored in the refrigerator for up to one week.)
Preheat a gas or charcoal grill.
Remove the cold log of butter from the freezer and unwrap. Shuck the oysters and discard the top shell, leaving the oysters on the bottom half shell. Slice thin rounds of butter, about 1 1/2 teaspoons each, and place 1 round on top of each oyster. Place the oysters on the heated grill, close the grill cover, and cook, covered, until the butter is melted and bubbly, and the oysters are no longer opaque and have curled around the edges, about 4 minutes.
Yield: 4 ρ 6 servings (24 baked oysters)