Ingredients:

  • 2 tbsp Extra Virgin Olive Oil
  • 1 large Yellow Onion, finely diced
  • 3 cloves Garlic, minced
  • 2 x 28 oz cans Whole Peeled San Marzano Tomatoes, crushed by hand
  • 1 tsp Granulated Sugar
  • 1 tsp Dried Oregano
  • 1/2 tsp Dried Basil
  • 1 tsp Flaky Sea Salt, plus more to taste
  • 1/2 tsp Black Pepper, freshly ground
  • 24–30 Jumbo Pasta Shells (Conchiglie, approx. 300 g)
  • 3 tbsp Unsalted Butter (optional, cut into small cubes)
  • 1 cup Low-Moisture Mozzarella, shredded (for topping)
  • 15 oz Whole Milk Ricotta Cheese (full-fat)
  • 10 oz Frozen Spinach, thawed and thoroughly squeezed dry
  • 1 large Egg, lightly beaten
  • 1/2 cup Freshly Grated Parmigiano Reggiano
  • 2 tbsp Fresh Parsley, finely chopped
  • 1 tbsp Fresh Basil, finely chopped
  • 1 medium Lemon, Zest only
  • 1 tsp Flaky Sea Salt (for filling)
  • 1/2 tsp Black Pepper (for filling)

Instructions:

  1. Sauté the Aromatics: Heat olive oil in a saucepan over medium heat. Add diced onion and sauté until softened and translucent (6-8 minutes). Add garlic and sauté for 1 minute until fragrant.
  2. Simmer the Sauce: Stir in the crushed San Marzano tomatoes, sugar, oregano, basil, salt, and pepper. Bring to a low simmer, then reduce heat and cook gently for 15 minutes, stirring occasionally. Adjust seasoning to taste.
  3. Prep the Baking Dish: Pour about 2 cups (approximately half) of the sauce into the bottom of the 9x13 inch baking dish, spreading evenly. Set aside.
  4. Cook the Shells (Al Dente): Bring a large pot of salted water to a rolling boil. Add the jumbo shells and cook for 2 minutes less than the package directions. Drain immediately and rinse quickly with cold water to stop the cooking process. Lay them out on a clean tea towel.
  5. Prepare the Spinach: Ensure the thawed spinach is squeezed completely dry, removing all excess moisture. Chop coarsely.
  6. Mix the Filling: In a large bowl, combine the ricotta cheese, dried spinach, beaten egg, Parmigiano Reggiano, parsley, basil, lemon zest, salt, and pepper. Mix thoroughly until uniform.
  7. Stuff the Shells: Transfer the ricotta mixture into a piping bag or use a small spoon. Carefully fill each shell, ensuring it is packed tightly.
  8. Arrange and Top: Place the stuffed shells open-side-up, tightly packed, into the baking dish atop the layer of tomato sauce.
  9. Sauce and Cheese: Pour the remaining tomato sauce over the shells, ensuring they are partially covered. Scatter the shredded mozzarella cheese evenly over the top. Dot with butter cubes if using.
  10. Bake (Covered): Cover the baking dish tightly with foil. Bake in a preheated oven at 375°F (190°C) for 20 minutes.
  11. Bake (Uncovered): Remove the foil and bake for an additional 10 minutes, or until the cheese is melted, golden brown, and the sauce is bubbling nicely around the edges.
  12. Rest and Serve: Allow the dish to rest for 5-10 minutes before serving. Garnish with fresh basil or Parmesan shavings.