Baked Spinach-Ricotta Stuffed Shells with Lemony Tomato Sauce

Make it

Instructions

1. 01

   Heat the oven and prepare the baking dish

   Position a rack in the center of the oven and heat the oven to 375°F. Lightly oil a 9-by-13-inch baking dish with a small amount of olive oil from the measured supply, then set the dish beside the stovetop. Set out a large pot, colander, large skillet, mixing bowl, and foil. | Why: Heating the oven now ensures it is fully hot when the assembled shells are ready to bake.

2. 02

   Boil and drain the shells

   Pour 4 l water into the large pot, cover, and bring it to a rolling boil over high heat. Add 1 tbsp kosher salt and 24 each jumbo pasta shells, then stir gently for the first minute to prevent sticking. Cook uncovered until the shells are flexible but still quite firm in the center, about 8 minutes or 2 minutes less than the package's al dente time. Reserve 120 ml of the cooking water, then drain the shells in the colander and rinse briefly under cool running water. Spread them in a single layer on a clean tray so they do not stick. | Why: Slightly undercooking and cooling the shells keeps them intact for stuffing and prevents mushiness after baking.

3. 03

   Make the spinach-ricotta filling

   Wash 170 g baby spinach in a colander, spin or pat it completely dry, and finely chop it. In the mixing bowl, combine the spinach with 425 g whole-milk ricotta cheese, 1 each large egg, 50 g grated Parmesan cheese, 2 tsp lemon zest, 2 tbsp chopped fresh parsley, 1/2 tsp kosher salt, and 1/4 tsp black pepper. Stir until evenly combined; the filling should be thick enough to mound on a spoon. | Why: Thoroughly drying the spinach prevents a watery filling, while egg and cheese help it set into a tender, sliceable center.

4. 04

   Simmer the lemony tomato sauce

   Heat 1 tbsp olive oil in the large skillet over medium heat until it shimmers. Add 3 each garlic cloves and 1/4 tsp crushed red pepper flakes; stir for 30 seconds, just until fragrant and not browned. Pour in 800 g crushed tomatoes, then season with 1/2 tsp kosher salt and 1/4 tsp black pepper. Bring the sauce to a gentle bubble, reduce the heat to medium-low, and simmer uncovered for 10 minutes, stirring occasionally. If it becomes thicker than a loose marinara, stir in enough reserved pasta water to loosen it. | Why: Briefly blooming the garlic and pepper in oil builds flavor, and simmering concentrates the tomatoes before baking.

5. 05

   Fill and assemble the shells

   Spoon about 2 tablespoons of the filling into each cooled shell, taking care not to split them. Spread two-thirds of the tomato sauce in the oiled baking dish and arrange the filled shells seam-side up in one snug layer. Spoon the remaining sauce over the centers, leaving some ridges exposed for texture. Scatter 170 g shredded mozzarella cheese evenly over the shells, then cover the dish tightly with foil. | Why: A layer of sauce beneath and above the shells keeps the pasta moist while the exposed edges retain a pleasing baked texture.

6. 06

   Bake, rest, and serve

   Place the covered dish on the center rack of the already heated 375°F oven and bake for 15 minutes. Carefully remove the foil, return the dish to the oven, and bake uncovered for 10 to 12 minutes more, until the sauce is bubbling around the edges, the mozzarella is browned in spots, and the center reaches 165°F. Rest the dish on a heatproof surface for 10 minutes. Sprinkle with the remaining parsley, then serve 6 shells per portion with sauce spooned from the dish. | Why: Covered baking heats the filling gently, while the uncovered finish browns the cheese and the rest lets the sauce settle for cleaner serving.