Leek and Gnocchi Bake With Three Cheeses and Crispy Prosciutto

Ingredients

• 2 tablespoons extra-virgin olive oil (EVOO)
• 8 thin slices prosciutto, halved crosswise
• 2 leeks, trimmed halved lengthwise and cut crosswise 1/2 inch thick
• salt and pepper
• two 10- to 12-ounce packages fresh potato gnocchi
• 2 tablespoons butter
• 2 tablespoons flour
• 2 cups milk
• ground nutmeg, to taste
• 1 cup grated fontina or fontina valle d'aosta cheese (3 generous handfuls)
• 1/2 cup grated asiago cheese
• 1/2 cup grated parmigiano-reggiano cheese

Directions

1. 1

   In a large skillet, heat the EVOO, 2 turns of the pan. Working in batches if necessary, add the prosciutto in a single layer and cook, turning once, until crisp, about 2 minutes. Drain on paper towels. Add the leeks to the skillet and cook until tender, 8 to 10 minutes; season with salt and pepper.

2. 2

   Bring a large pot of water to a boil, salt it, add the gnocchi and cook until the gnocchi float to the surface, about 3 minutes.

3. 3

   Meanwhile, in a medium saucepan, melt the butter over medium heat. Whisk in the flour for 1 minute, then whisk in the milk; season with salt, pepper and nutmeg. Cook until thickened, 5 minutes. Stir in the fontina and asiago until melted.

4. 4

   Preheat the broiler. Drain the gnocchi and place in a casserole dish. Stir in the leeks and cheese sauce and top with the parmigiano-reggiano. Broil the casserole until browned, 3 to 4 minutes. Top with the prosciutto.