Grilled Oysters with Ginger, Soy, and Jam

OK, I know it sounds weird: oysters grilled with berry jam and soy sauce. And I wish I could point to a barbecue tradition of great antiquity for the combination; for example, that’s how the Belgae grilled oysters when the Romans conquered the Germano-Celtic tribes that would give their name to Belgium. But they didn’t and I can’t. So you’re just going to have to trust me that the yin and yang of sweet berry jam and mirin (sweetened rice wine) contrasted with the briny tang of oysters and s