1. Precook pie crust.
2. Aftr preparing the fiddleheads for cooking, sauté onion and fiddleheads in olive oil for six to eight minutes then place in crust.
3. Sprinkle cheese evenly over the top. Blend eggs, mustard, flour, cream, and pour over other ingredients.
4. Bake at 350F for about 50 minutes to endure that fiddleheads are thoroughly cooked. When a knife inserted into the center comes out clean, pie is cooked. This dish may be served hot or cold.
5. Serves 3-5.