Preheat the oven to 190°C (375°F).

In a large pot, boil salted water and cook the jumbo pasta shells until al dente, about 8-10 minutes. Drain and cool.

In a skillet, heat olive oil and sauté minced garlic until fragrant. Add chopped spinach and cook until wilted, about 3-4 minutes.

In a bowl, mix spinach with ricotta, mozzarella, Parmesan, an egg, and a hint of nutmeg until creamy.

Spread marinara sauce in a baking dish, fill shells with the mixture, place them seam-side up, pour remaining sauce over, and sprinkle extra mozzarella on top.

Cover with foil and bake for 25 minutes. Remove foil and bake for another 10 minutes until bubbly and golden.

Let rest for 5 minutes and garnish with chopped basil or parsley before serving.