Step 1

Cook the pasta shells according to the package directions. Drain and rinse under cool water.

Step 2

While the pasta is cooking, make the filling by combining the spinach, artichoke hearts, ricotta, shallot, garlic, 2 oz of the grated asiago, and 4 oz of the grated mozzarella. Mix well and season, to taste, with salt and pepper. Mix in the egg.

Step 3

For the asiago cream, melt the butter in a large saucepan over medium heat. Once melted, whisk in the flour until a paste forms and then cook for a minute.

Step 4

Slowly stream in the milk, whisking constantly. Bring the mixture to a gentle simmer, stirring frequently, and cook until it is thickened and creamy. Stir in the remaining asiago cheese and cook until the cheese is melted. Season, to taste, with salt and pepper.

Step 5

Butter a 9 x 13-inch baking dish and pour roughly half of the asiago cream into the bottom of the dish, spreading it out evenly.

Step 6

Fill the pasta shells with the ricotta filling and place them in the cream sauce in the baking dish.

Step 7

Once all the shells have been filled and placed in the dish, pour the remaining asiago cream over top of them as evenly as possible.

Step 8

Top with the remaining grated mozzarella cheese.

Step 9

Transfer to a 350°F oven and bake for 25 minutes, or until bubbly and golden in spots. If desired, broil the top for a minute, watching carefully, until a deeply golden crust forms on top of the shells.

Step 10

Cool in the pan for about 10 minutes. Garnish with chopped parsley and serve.