Preheat oven to 350 degrees. Butter a 9-inch deep dish pie pan.

Thaw spinach and drain well, pressing out all liquid.

Melt 2 tablespoons of the butter; set aside to cool.

In a medium mixing bowl, using a fork stir together spinach, cooked rice and egg. Add cooled butter. Season to taste with salt and pepper. Press over the bottom and up the sides of the prepared pie pan.

Bake for 15 minutes or just until set. Remove from oven and set aside to cool for at least 20 minutes.

In a small bowl, sift together flour, curry powder, and garlic powder. Set aside.

In a small bowl, whisk together milk and Dijon mustard. Set aside.

In a large skillet or sauté pan over medium heat, melt remaining 2 tablespoons butter. Add sliced mushrooms and sauté until moisture evaporates and mushrooms are starting to turn golden.

Reduce heat to low, sprinkle flour mixture over the mushrooms and cook, stirring, for 3 minutes. Slowly pour in the milk mixture, stirring constantly. Increase heat to medium and continue cooking, stirring, until sauce is just beginning to thicken (don’t cook until really thick). Turn off heat and season to taste with salt, pepper and cayenne pepper.

Spread chopped turkey evenly over cooled spinach-rice crust. Top with grated cheese and chopped onion. Spread mushroom sauce evenly over the top and bake for 30 to 40 minutes or until pie is hot and bubbly.