01 -
Preheat oven to 175°C (350°F).
02 -
Spread a 2.5 cm layer of spaghetti sauce on the base of one or two large glass baking dishes. Add extra sauce if a saucier result is preferred.
03 -
Boil pasta shells in salted boiling water with a drizzle of oil for approximately 11 minutes until al dente. Drain and set aside.
04 -
While pasta is cooking, dice onion, mince garlic, and chop spinach. Measure remaining ingredients for efficient assembly.
05 -
Sauté diced onions and minced garlic over medium-high heat in a small pan until softened and fragrant.
06 -
In a large mixing bowl, combine ricotta, grated parmesan, chopped spinach, Italian seasoning, garlic powder, dried parsley, dried basil, crushed red pepper, dried oregano, salt, and black pepper. Fold in the sautéed onion and garlic. For a firmer filling, whisk egg and gently incorporate.
07 -
Evenly spoon the prepared ricotta spinach filling into each cooked pasta shell. Arrange stuffed shells in the prepared baking dish.
08 -
Optionally drizzle additional spaghetti sauce over stuffed shells or leave uncovered for a crispier top. Sprinkle generously with mozzarella and extra parmesan. Add extra crushed red pepper flakes and dried basil if desired.
09 -
Cover baking dish loosely with foil and bake for 20–30 minutes, until the filling is heated through and sauce is bubbling. Remove foil if cheese has not melted, and bake an additional 5–10 minutes until golden and bubbling.