Egg Roulade Stuffed with Proscuitto, Spinach and Roasted Red Pepper
5 tablespoons unsalted butter, plus extra
6 tablespoons all-purpose flour, plus extra
1¼ cups whole milk, warmed
4 large egg yolks, room temperature
½ teaspoon kosher salt
¼ teaspoon ground black pepper
6 large egg whites, room temperature
Pinch of cream of tartar
2 tablespoons olive oil
10 ounces baby spinach
1 teaspoon minced garlic
8 ounces coarsely grated fontina or Gruyere cheese (about 2 cups)
3 ounces thinly sliced prosciutto
¾ cup roasted red peppers, cut into thin strips
Heat the oven to 350 degrees. Use a bit of butter to lightly coat a 15-by-10-inch rimmed baking sheet. Line the baking sheet with kitchen parchment, leaving about 1 inch hanging over each of the pan's shorter sides, then lightly butter the parchment. Sprinkle the parchment with a bit of flour, then tilt the pan and tap gently to spread the flour and discard any excess.
In a small saucepan over medium heat, melt the 5 tablespoons of butter. Add the 6 tablespoons of flour and cook, stirring, for 3 minutes. Add the milk in a stream, whisking, and bring the mixture to a boil, whisking the entire time. Turn down to a simmer and cook for 5 minutes. Transfer the mixture to a large bowl and whisk in the egg yolks, one at a time. Stir in the salt and pepper.
In a separate large bowl, use an electric mixer to beat the egg whites with the cream of tartar and a pinch of salt until they form soft peaks. Stir a quarter of the whites into the yolk mixture, then fold in the rest, gently but thoroughly. Pour the batter into the prepared sheet pan and carefully smooth with a metal spatula.
Bake on the oven's middle shelf, rotating the pan after 7 minutes. Bake for another 7 to 8 minutes, or until golden and firm to the touch. Set the pan on a rack to cool slightly. Increase the oven to 375 degrees.
While the roulade is baking, in a large skillet over high, heat the oil. Add half of the spinach and cook, stirring, until it starts to wilt, then add the remaining spinach and cook until all the spinach has wilted. Add the garlic and cook, stirring, for 1 minute. Transfer the mixture to a colander to drain, pressing lightly on the spinach to drain any excess liquid. Season with salt and pepper.
Use a bit of butter to lightly coat one side of a sheet of kitchen parchment cut to the same size as the egg sponge. Place the parchment, buttered side down, onto the top of the sponge. Cover with a damp kitchen towel, then carefully invert the sponge onto a work surface. Peel off the parchment from the top of the sponge.
Sprinkle the cheese evenly over the sponge, leaving a ½-inch border on all sides. Top the cheese with the prosciutto in an even layer, followed by the spinach. Arrange the red pepper strips in one line down the center (starting and ending at the short sides).
Starting with one of the longer sides, use the towel to help roll up the sponge, enclosing the filling, jelly roll-fashion. Carefully pick up the roulade and place it seam side down on the baking sheet. Bake it in the middle of the oven until the cheese has melted, 8-10 minutes. Use a serrated knife to cut crosswise into ½-inch thick slices.
Serves eight.
Nutrition values per serving: 340 calories, 26 g fat (13 g saturated; 0 trans), 160 mg cholesterol, 11 g carbohydrate, 2 g fiber, 3 g sugar, 17 g protein, 770 mg sodium.
Sara Moulton for The Associated Press