Serves 4 to 6
Prosciutto is often used in Italy to add extra flavor to vegetables, but this dish is delicious even without it, or with thin slices of ham substituted. The recipe can be turned into a perfect brunch dish with the addition of one poached egg per serving.
- 2 tablespoons unsalted butter
- 6 medium leeks, white and light-green parts, ends trimmed, halved lengthwise but still attached at root end
- ¼ teaspoon kosher salt
- 3 ounces prosciutto, thinly sliced
- 4 ounces Gruyère, shredded
- ½ cup coarsely chopped walnuts
Preheat oven to 400 degrees. Spread the butter in the bottom of an 11-by-7-inch gratin dish.
Arrange the halved leeks in the bottom of a large skillet in one layer, and add water to cover. Bring to a simmer, and cook until the leeks are just tender, about 10 minutes.
Fish the leeks out with tongs and a spider, draining off excess water as you go, and arrange in one layer in the baking dish, rolling to coat in the butter. Season with the salt. Tear the prosciutto into rough shreds, and layer these over the leeks. Bake until the prosciutto is crisp, about 20 minutes.
Sprinkle over the leeks the cheese, then the walnuts, and bake until the cheese is melted and bubbly, about 8 to 10 minutes. Serve hot.