Cheesy Baked Pasta with Radicchio
- 2 tablespoons olive oil
- 2 medium-size red onions, thinly sliced
- 1 large head radicchio, cored and sliced into 1/2-inch-thick ribbons
- 2 large garlic cloves, thinly sliced
- 1 tablespoon red wine vinegar
- 3 1/2 tablespoons kosher salt divided
- 6 ounces softened goat cheese, crumbled (about 1 1/2 cups)
- 1 1/2 cups heavy cream
- 3 quarts Water
- 1 pound uncooked short pasta (such as gemelli, casarecce, or strozzapreti)
- 1/4 teaspoon black pepper
- 1/8 teaspoon freshly grated nutmeg
- 8 ounces fontina cheese, cut into 1/2-inch cubes (about 2 cups),divided
- 4 ounces thinly sliced prosciutto torn into 1-inch pieces
- Unsalted Butter softened, for greasing baking dish
- 2 ounces Parmigiano-Reggiano cheese, grated (about 1/2 cup)
