tablespoon butter 1 1/2 tablespoons all-purpose flour 1 cup milk 1/8 teaspoon salt Pinch white pepper Pinch freshly grated nutmeg 1 ounce grated cheese, such as Swiss, Gruyere, or Emmenthaler In a small saucepan melt the butter over medium-high heat. Add the flour and cook, stirring constantly, until the roux is pale yellow and frothy , about 1 minute. Do not allow the roux to brown. Slowly whisk in the milk and continue to whisk until the sauce thickens and comes to a boil, about 2 to 3 minutes. Reduce the heat to a simmer and season with the salt, pepper and nutmeg. Allow to simmer for 2 to 3 minutes. Stir in the cheese and whisk until melted. If the sauce seems too thick, thin with a little milk. Use sauce immediately or refrigerate, surface covered with plastic wrap , for several days in the refrigerator. Yield: about 1 cup 3/4 pound russet potatoes (about 1 large) 4 ounces pancetta or bacon, cooked until crisp , drained and crumbled 1 large egg, lightly beaten 1/2 teaspoon salt 1/2 teaspoon black pepper Vegetable oil, for frying Peel the potato and put in cold water. Using a mandoline , grater , or food processor , coarsely grate the potato. Place in a fine-mesh sieve or strainer and squeeze out all of the potato liquid over a bowl. After the starch has settled to the bottom of the bowl, carefully pour off the clear liquid, reserving the starch. Add the grated potato to the starch in the bowl, along with the reserved crumbled bacon, egg, salt and pepper. Heat a nonstick pan with a small amount of oil in the bottom of the pan. When the oil is hot, take about one-quarter of the potato mixture in the palm of your hand and, using the other hand, flatten and squeeze to remove any excess liquid. Place the potato mixture in the heated pan and cook, pressing down with a spatula to flatten, until crispy and golden, about 3 minutes on each side. Transfer to a paper lined baking sheet and keep warm in the oven while you cook the remaining potato cakes.