Preheat your oven to 375°F (190°C).

In a large pot, bring salted water to boil and cook jumbo shells for 9-11 minutes until al dente. Drain and set aside.

In a skillet, heat olive oil and sauté minced garlic for 1-2 minutes. Add spinach and cook until wilted, about 3-4 minutes. Season with salt and pepper.

In a mixing bowl, combine the ricotta, mozzarella, Parmesan, sautéed spinach, egg, and nutmeg until well mixed.

Spread a thin layer of marinara sauce in a baking dish. Stuff each shell with the cheese mixture and place in the dish seam side up.

Pour remaining marinara sauce over the shells and sprinkle more mozzarella on top.

Cover with foil and bake for 25 minutes, then uncover and bake for another 10 minutes until bubbly and golden.

Let cool for a few minutes, then garnish with basil or parsley and serve.