Directions

1. Make the shells: Bring a large pot of salted water to a boil. Add the pasta shells and cook until just slightly softened but still firm, about 7 minutes. Drain and rinse under cool water. Drizzle with oil and toss; set aside.
2. Heat the oil in a large non-stick skillet over medium-high heat. Add the onion and cook, stirring occasionally, until soft, about 4 minutes. Add the garlic and cook, stirring, 30 seconds. Add the sausage and cook, breaking it up with a wooden spoon, until browned, about 5 minutes. Add the spinach, ½ tsp salt and pepper to taste and stir until heated through, about 2 more minutes. Remove from heat and let cool completely.
3. Combine the spinach mixture, ricotta, 1 cup mozzarella, parmesan, parsley and 1 tsp salt in a bowl. Stuff each shell with about 2 tbsp filling, set aside.
4. Preheat oven to 350F. Make the cheese sauce: Melt the butter with garlic in a medium saucepan over medium heat. When the butter begins to foam, add the flour and whisk constantly until lightly golden, about 1 minute. Add the milk and cream, bring to a simmer and cook, whisking constantly, until the sauce is thick enough to coat a spoon, 2-3 minutes. Remove from the heat and whisk in the parmesan, ¼ tsp salt, and nutmeg to taste.
5. Brush a 9X13” baking dish with oil and pour in about ⅔ of the cheese sauce. Add the stuffed shells and top with the remaining cheese sauce. Cover with foil and bake 20 minutes. Uncover and top with marinara and 1 cup mozzarella; continue baking until the sauce is bubbly, 15-20 minutes more.