- 2 heads Chioggia or Treviso radicchio, quartered lengthwise, or red (Verona) radicchio, cut into 2-inch-wide wedges
- 2 tablespoons unsalted butter, plus butter for pan
- 2 tablespoons all-purpose flour
- 1½ cups milk
- 1 teaspoon kosher salt
- Freshly ground black pepper to taste
- ¼ cup freshly grated Parmesan cheese
- 8 very thin slices prosciutto
- Trim any stalks from the Chioggia or Treviso radicchio to ½ inch. Fill a large deep frying pan with salted water. Bring to a boil; lower to a simmer. Place the radicchio in the water in a single layer. Cover with a clean tea towel. Cook in barely simmering water for 30 minutes.
- While the radicchio is simmering, prepare the béchamel sauce: Melt the butter in a 2-quart saucepan. Add the flour and cook, stirring, over low heat for 5 minutes. Slowly add the milk, whisking briskly to prevent lumps; be sure to scrape the corners, where lumps can hide. Increase the heat to medium. Cook for several minutes, stirring occasionally, until thickened. Stir in the salt and pepper. Remove from the heat and stir in the Parmesan.
- Preheat the oven to 350°F.
- Butter an 8 × 8-inch baking dish. Drain the radicchio. Wrap each quarter in a slice of prosciutto. Or, if using Verona radicchio, divide the prosciutto as necessary to wrap each piece.
- Arrange in a single layer in the buttered pan. Spread with the béchamel, making sure to reach into the corners of the pan. Bake for 15 to 18 minutes, or until bubbly.