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Baked Vegetarian Stuffed Shells with ricotta and spinach in tomato sauce

Freezer-Friendly Vegetarian Stuffed Shells

This is a hearty and luxurious baked pasta dish featuring jumbo shells stuffed with a savory, cohesive filling of ricotta, spinach, and mushrooms, all smothered in marinara and melted cheese. Designed for convenience, it's perfect for making ahead and freezing for future easy meals.
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Prep Time 30 minutes
Cook Time 40 minutes
Total Time 1 hour 10 minutes
Servings: 6
Course: Main Course
Cuisine: Italian-American
Calories: 450
Ingredients Equipment Method Notes

Ingredients
  

  • 2 tablespoons olive oil
  • 1 medium yellow onion, finely diced
  • 8 oz cremini or baby bella mushrooms, finely chopped
  • 4-5 cloves garlic, minced
  • 5 oz fresh baby spinach
  • 1 large egg
  • 1 cup shredded mozzarella cheese, divided
  • 1/2 cup grated Parmesan cheese, divided
  • 1 teaspoon dried oregano
  • 1/4 teaspoon freshly grated nutmeg
  • Kosher salt, to taste
  • Black pepper, to taste

Equipment

  • Large pot
  • Colander
  • Large Skillet
  • Mixing bowls
  • 9x13 inch baking dish
  • Aluminum foil
  • Measuring cups and spoons
  • Knife
  • Cutting board
  • Spoon or cookie scoop
  • Cooling rack

Method
 

  1. Bring a large pot of well-salted water to a boil. Cook the jumbo shells for 2-3 minutes less than the package directions for al dente. Drain, rinse under cool water, drizzle with a little olive oil, and toss gently to prevent sticking.
  2. Heat olive oil in a large skillet over medium heat. Add the diced onion and cook until soft and translucent, about 5 minutes.
  3. Add the chopped mushrooms to the skillet. Cook, stirring occasionally, until they have released their water and are deeply browned, about 8-10 minutes.
  4. Add the minced garlic and cook for 1 minute until fragrant. Season generously with salt and pepper.
  5. Add the fresh spinach in handfuls, stirring until each batch wilts down before adding more. Cook for 1-2 minutes total. Remove the skillet from heat and let the mixture cool slightly.
  6. Preheat oven to 375°F (190°C). In a large mixing bowl, combine the ricotta, egg, 1/2 cup of the mozzarella, and 1/4 cup of the Parmesan. Add the dried oregano, nutmeg, a good pinch of salt, and several grinds of black pepper. Stir until well combined.
  7. Add the slightly cooled vegetable mixture from the skillet to the ricotta mixture. Fold together gently but thoroughly. Taste and adjust seasoning.
  8. Spread about 1 cup of the marinara sauce in the bottom of a 9x13 inch baking dish.
  9. Using a spoon or small cookie scoop, fill each par-cooked shell with the ricotta-vegetable mixture. Place each stuffed shell, opening side up, snugly into the sauced baking dish.
  10. Pour the remaining marinara sauce over the top of the stuffed shells, aiming to cover them lightly.
  11. Sprinkle the remaining 1/2 cup of mozzarella and 1/4 cup of Parmesan cheese evenly over the top.
  12. Cover the baking dish tightly with aluminum foil. Bake for 25 minutes.
  13. Carefully remove the foil and bake for an additional 10-15 minutes, until the cheese is melted and the sauce is bubbling around the edges. For a more golden top, broil for the last 1-2 minutes, watching closely.
  14. Remove the pan from the oven and let it rest on a cooling rack for 10 minutes before serving.

Notes

Undercook the pasta shells initially to prevent them from becoming mushy after baking. For the filling, ensure all vegetables are cooked to drive off excess moisture; if using frozen spinach, thaw and squeeze it completely dry in a kitchen towel. To freeze, assemble the dish completely but do not bake. Cover tightly and freeze. Thaw overnight in the refrigerator before baking as directed, adding a few extra minutes if needed. Variations include adding sun-dried tomatoes and pesto to the filling, mixing in cooked plant-based sausage or lentils, swapping spinach for kale, or using a creamy vodka sauce instead of marinara.