Ingredients

  • 1 1/2 pounds round or long radicchio, 2 or 3 firm heads
  • 4 tablespoons butter
  • 4 tablespoons extra-virgin olive oil
  • 1 medium-large onion, peeled and sliced in 1/4-inch-thick half-moons (2 cups)
  • 3 plump garlic cloves, smashed and peeled
  • 1 teaspoon coarse sea salt or kosher salt, or to taste
  • 1 tablespoon red wine vinegar
  • Freshly ground black pepper to taste
  • 1 cup freshly grated Grana Padano or Parmigiano-Reggiano
  • A heavy saute pan, 12-inch diameter or wider, with a cover
  • A baking dish or shallow casserole, 9 by 13 inches or similar size

Method

  • Trim the radicchio heads, discarding wilted or bruised outer leaves and slicing off the very bottom if tough and discolored (dont remove the core).
  • Slice the heads in quarters or sixths, into wedges about 3 inches wide.
  • Cut through the core, so the leaves are held together.
  • Arrange a rack in the center of the oven, and heat to 375 .
  • Put the butter and 2 tablespoons of the olive oil in the skillet, and set over moderate heat.
  • When the butter is melted and foaming, stir in the onion and garlic and cook for a minute, then lay in all the radicchio wedges in one layer.
  • Sprinkle on the salt, cover the pan, and cook slowly, turning the wedges over and stirring the onion every couple of minutes.
  • After 10 minutes or so, when the radicchio is softened slightly but still firmly holding its shape, stir the vinegar with 1/2 cup water and pour into the pan.
  • Raise the heat a bit and bring the liquid to the boil, turning the wedges and stirring.
  • Cook for a couple more minutes, until the pan juices are reduced and syrupy and the wedges are lightly caramelized.
  • Remove the skillet from the heat, and arrange the radicchio wedges in the baking dish in one layer.
  • Spoon the onion all around, and pour the skillet liquid over.
  • Drizzle on the remaining 2 tablespoons olive oil, season with freshly ground black pepper, and sprinkle the grated cheese in an even layer, covering the radicchio.
  • Tent the dish with aluminum foil, pressing it against the sides.
  • Bake covered for about 20 minutes, remove the foil, and bake another 5 minutes or more, until the radicchio wedges are tender and moist and glazed golden on top.