Sea Scallops With Miso Mustard Sauce without vinegar

12 sea scallops salt and pepper 1 garlic clove , minced all-purpose flour , for dusting 2 tablespoons white miso or 2 tablespoons miso 1 tablespoon mirin 1[...]

red grapefruit , cut in half (1 lb.) 1 tablespoon white miso 1 tablespoon rice vinegar 1 tablespoon sake 2 tablespoons butter 2 tablespoons minced shallots 2[...]