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Baked Shells with Spinach and Ricotta

One 9-by-13-inch bake, about 24 stuffed shells Active 35 min Total 1 hr 20 min

Large pasta shells make a generous baked dish without requiring layers. Their pockets hold spinach and ricotta, while a simple tomato sauce keeps the edges moist. A little mozzarella melts across the top, making the shells easy to share straight from the baking dish. The filling is deliberately soft but not wet; squeezing the spinach well is the key. Cook the shells slightly short of tender before filling so they can finish in the sauce without falling apart.

Jump to the ingredients

Spinach-ricotta stuffed pasta shells baked in tomato sauce with melted mozzarella.

Dry spinach makes a better filling

Thawed frozen spinach contains more water than it first appears to. Squeeze handfuls firmly over a sieve, then press again in a clean towel if needed. The compact leaves should no longer drip when squeezed. This keeps the ricotta mixture concentrated and stops greenish water from collecting in the sauce. Break up the squeezed spinach thoroughly before adding it to the bowl, or a few shells will get dense clumps while others contain only cheese.

A sauce with a clear ingredient list

Plain crushed tomatoes give you control of the flavor. Many prepared pasta sauces contain black pepper, chili, or an unspecified seasoning blend, even when the front label does not say spicy. Here, onion and a modest amount of garlic soften before the tomatoes simmer. The garlic is cooked through rather than left raw. Basil joins at the end. The sauce should remain loose enough to flow around the shells, not reduce into a thick paste.

Filling without a piping bag

A teaspoon is enough to fill each shell, and a little variation in shape is part of the dish. Arrange the cooked shells on a lightly oiled tray while making the filling so they do not stick into one mass. Hold a shell in your palm and tuck filling into its curve rather than forcing it wide open. Extra cooked shells are useful insurance against a tear. Rest the baked dish before serving so the cheese settles and the portions lift more cleanly.

Ingredients

  • 2 tablespoons olive oil, divided
  • 1 small yellow onion, finely diced
  • 1 small garlic clove, minced
  • 1 can (28 ounces/795 g) plain crushed tomatoes, without added pepper or chili
  • 3/4 teaspoon fine salt, divided, plus 1 teaspoon for pasta water
  • 2 tablespoons chopped fresh basil
  • 8 ounces (225 g) jumbo pasta shells, about 28 shells
  • 1 package (10 ounces/285 g) frozen chopped spinach, thawed
  • 1 container (15 ounces/425 g) whole-milk ricotta
  • 1 large egg
  • 1/3 cup (30 g) finely grated Parmesan
  • 1 cup (115 g) shredded low-moisture mozzarella

Set out

9-by-13-inch baking dish, Large pasta pot, Medium saucepan, Mixing bowl, Clean kitchen towel, Instant-read thermometer

Allergens

Wheat, milk, egg. Check ingredient labels and substitutions.

Make it

  1. Heat the oven to 375°F/190°C. Heat 1 tablespoon oil in a saucepan over medium heat. Add the onion and cook for 6 minutes. Add garlic and cook for 1 minute.
  2. Add the crushed tomatoes and 1/2 teaspoon salt. Simmer gently for 12 minutes, then stir in the basil. Spread half the sauce in a 9-by-13-inch baking dish.
  3. Meanwhile, boil the shells in water seasoned with the additional teaspoon salt for 2 minutes less than the package time. Drain carefully, drizzle with the remaining tablespoon oil, and spread on a tray to cool enough to handle.
  4. Squeeze the thawed spinach very dry in a clean towel, then break it apart. Mix with the ricotta, egg, Parmesan, and remaining 1/4 teaspoon salt.
  5. Fill about 24 intact shells with the spinach mixture, using roughly 1 1/2 tablespoons per shell. Arrange open-side up in the dish; reserve any extra cooked shells for another use.
  6. Spoon the remaining tomato sauce around and lightly over the shells. Scatter the mozzarella evenly on top. Cover with foil without pressing it against the cheese.
  7. Bake for 25 minutes. Uncover and bake for 8–10 minutes more, until bubbling with lightly golden cheese and a center temperature of 165°F/74°C. Rest for 10 minutes before serving.

A useful detail

The package weight includes a few spare shells in case some split. If your shells are unusually large, use the same filling divided among fewer shells rather than stretching it thin.

Make it your own

  • Replace half the spinach with finely chopped cooked broccoli, squeezed or blotted dry.
  • Use plain crushed yellow tomatoes for a softer-colored sauce, checking that no pepper or chili is added.

Keep it well

Refrigerate portions in shallow containers within 2 hours at 40°F/4°C or below for up to 4 days. Freeze baked portions for up to 2 months. Reheat covered to 165°F/74°C, adding a spoonful of water around the shells if the sauce has thickened.