How to make
The oven is preheated to 190°C / 375°F. A medium baking dish is lightly brushed with olive oil so the tomato sauce does not catch on the bottom during baking.
A large pot of salted water is brought to a boil. The jumbo conchiglie are cooked for 8-9 minutes, just until flexible but still firm. They should not be fully cooked, because the stuffed pasta shells will soften further in the oven.
The pasta is drained carefully and spread on a tray in a single layer. A little olive oil is drizzled over the shells and they are left to cool for a few minutes. This keeps them separate and makes them easier to fill without tearing.
For the spinach and ricotta filling, the fresh spinach is placed in a hot dry pan for 2-3 minutes, just until wilted. It is then cooled slightly, squeezed well to remove excess moisture, and chopped. This step is important because watery spinach can make the filling runny.
The ricotta is mixed in a bowl with the chopped spinach, egg, grated Parmesan, grated mozzarella, finely minced garlic, nutmeg, salt, and black pepper. The mixture should be creamy but thick enough to hold inside the conchiglie.
For the tomato base, olive oil is warmed in a small saucepan over medium heat. The garlic is cooked for about 30 seconds, then the tomato passata, oregano, sugar, and salt are added. The sauce simmers for 8-10 minutes, until slightly thicker and more aromatic.
Most of the tomato sauce is spread over the bottom of the baking dish. Each pasta shell is filled with a spoonful of ricotta and spinach mixture, then arranged open side up in the sauce. The shells can sit close together, but they should not be pressed too tightly.
The remaining tomato sauce is spooned around and lightly over the edges of the stuffed shells. A little Parmesan is scattered on top for a savory baked finish.
The dish is covered with foil and baked for 20 minutes. The foil is then removed and the baked conchiglie continue cooking for another 10-15 minutes, until the sauce bubbles gently and the pasta edges look lightly golden.
The stuffed conchiglie are left to rest for 5 minutes before serving. This short pause helps the filling settle and makes the pasta easier to lift from the dish.
Baked conchiglie stuffed with ricotta and spinach are best served warm, with extra Parmesan if desired. A crisp green salad and simple garlic bread go well with the creamy filling and bright tomato sauce.
Leftovers can be stored in an airtight container in the refrigerator for up to 3 days. They reheat well in a covered ovenproof dish at 170°C / 340°F for 15-20 minutes, or in the microwave in short bursts.
For more comforting pasta dishes, try the creamy tortellini with ricotta and spinach and the hearty oven baked spinach and ricotta lasagna for your next cozy meal.
