Pre heat oven to 400 degrees.

Fill a large stock pot with salted water and boil pasta for 8-9 minutes. Do not over cook or they will break while stuffing. Cook a few extra because they tear easily.

While shells are boiling, chop your mushrooms and garlic. Place frozen spinach in the microwave for two minutes to help defrost.

Drain pasta and rinse with cold water to stop cooking.

In a large pan, add olive oil. Sauté mushrooms about 3-4 minutes until browned around the edges. Add in two of the chopped cloves of garlic. Sauté until fragrant. Stir in the 1/2 cup of wine. Add in salt, pepper and nutmeg. Add in spinach and cook until the moisture has completely evaporated.

Set mixture aside in a small bowl.

In the same pan over medium high heat, melt the butter. Stir in the red pepper flakes, oregano and remaining garlic. Stir until spices bloom and butter becomes foamy. Pour in the marinara sauce and heat through about 3 minutes on simmer.

Pour sauce into a 9 x 13 inch oven proof dish.

To the mushroom mixture, stir in the ricotta, 4 oz of cheese and egg. Fill the shells with spoonfuls of the spinach mixture and place in the marinara sauce open side up. Sprinkle with remaining cheese and panko.

Bake at 400 degrees until the sauce is bubbling and the cheese is golden brown and melted: about 20 minutes.