GRILLED SCALLOP-STUFFED SWEET ONIONS

Grilled Scallop-Stuffed Sweet Onions image

Provided by Martha Stewart

Yield Serves 4

Number Of Ingredients 9

4 large sweet onions, such as Vidalia, Maui, or Walla Walla
2 tablespoons olive oil
Salt and freshly ground black pepper
1/2 cup sake
1/4 cup soy sauce, plus more for topping onions
2 tablespoons mirin
4 very large diver or day-boat sea scallops
4 thin slices prosciutto
2 tablespoons unsalted butter

Steps:

Preheat oven to 325 degrees. Place onions in their skins in an 11 1/2-by-8-inch metal baking pan. Rub onions with oil and season with salt and pepper. Cover pan tightly with parchment paper-lined aluminum foil. Roast until onions are tender, but still retain their shape, about 2 1/2 hours. Remove onions from baking pan, reserving pan; let stand until cool enough to handle.
Cut off the top third of each onion; set aside. Cut a hole in the center of each onion large enough to hold a scallop.
Place baking pan on the stove over high heat. Add sake, and stir using a wooden spoon, scraping up the browned bits. Add onion centers, soy sauce, and mirin; cook, stirring, until onions are soft. Pour mixture into a small saucepan; set aside.
Season scallops with salt and pepper. Preheat a grill pan over high heat. Reheat sake mixture and season with salt and pepper; keep warm until ready to use.
Place scallops on grill and cook, turning once, just until grill marks appear on prosciutto, about 30 seconds per side. Wrap each scallop in a piece of prosciutto, enclosing completely. Stuff a scallop into each onion. Top each with 1/2 teaspoon butter, cover with reserved onion tops, and place on grill pan. Cook onions until heated through and skin is blackened, 6 to 8 minutes.
Remove blackened skin and divide onions among 4 serving plates. Drizzle each with sake mixture and serve immediately.