Cacio e Pepe-Stuffed Shells with Crispy Crumbs

Instructions

• 1Insert the wire rack into position 6. Meanwhile, continue to the next step.
• 2Place the breadcrumbs in a bowl, add the oil, thyme, salt and pepper. Stir until combined. Spread crumbs evenly onto roasting pan.
• 3Once preheated, place the pan in the oven and start the timer. When the Rotate Remind signals, stir the crumbs and continue cooking. Meanwhile, cook the pasta.
• 4The crumbs should be golden brown. If not, give it a bit more.
• 5Bring a large pot of salted water to a boil over high heat. Add the pasta and cook according to the package instructions, until al dente. Drain reserving ½ cup 4 fl oz of the pasta water.
• 6Place the shells, with the open side up, in a single layer on a baking sheet and let cool to room temperature. Meanwhile, make the cheese filling.
• 7In a large bowl, stir together the ricotta, whole egg, egg yolk, lemon zest, pecorino, Parmesan, 1 tsp. kosher salt and 1 tsp. pepper. Transfer the filling to a pastry bag with a large plain tip.
• 8Pipe the filling into the cooled pasta shells, dividing it evenly and filling each shell about halfway.
  Tip: The filled shells can be stored, covered, in the refrigerator overnight.
• 9In a saucepan over medium-low heat, melt the butter. Whisk in the flour and cook, whisking occasionally, until a smooth paste forms, about 1 minute. Add 2 tsp. pepper and cook, stirring occasionally, until the mixture smells toasty, about 3 minutes.
• 10Slowly pour in the milk, whisking constantly until smooth. Increase the heat to medium-high and bring to a simmer, then reduce the heat to low and cook, whisking constantly to prevent the bottom from burning, for 5 minutes, until the mixture is thick and velvety. Whisk in the pecorino and Parmesan, then add 5 tablespoons 2½ fl oz of the reserved pasta water until smooth. Remove from the heat and season generously with about 2 tablespoons salt, or to taste.
• 11The oven will preheat. Meanwhile, continue to the next step.
• 12Brush a 5-quart braiser with olive oil. Spread one-third of the béchamel on the bottom of the prepared pan, then arrange the filled shells, open side up, on top of the béchamel. Ladle the remaining béchamel over the shells.
• 13Sprinkle with the breadcrumbs, pecorino and pepper.
  Tip: Crumbs can be transferred to a food processor and pulsed briefly into smaller crumbs.
• 14Once preheated, place in the oven and start the timer.
• 15The sauce should be bubbling, the breadcrumbs dark golden brown and pasta shells very tender. If not, give it a bit more.
• 16Let cool for a few minutes, then drizzle lightly with olive oil and sprinkle with flaky sea salt. Serve immediately.