Mollie Katzens Mushroom Yogurt Pie with Spinach Crust

Name: Mollie Katzen's Mushroom Yogurt Pie with Spinach Crust
Ingredients: For the Spinach Crust; 3/4 pound spinach, chopped very fine; 3 tablespoons butter; 3/4 cup unbleached white flour; 3/4 cup wheat germ; 1/4 teaspoon salt; Dash of nutmeg; For the Mushroom Yogurt Pie; 1 Spinach crust; 1 tablespoon butter; 1 cup minced onion; 1/2 teaspoon salt; 12 ounces mushrooms, sliced; 2 tablespoons fresh lemon juice; 3 tablespoons flour (white or whole wheat); 1 egg (at room temperature); 1 cup firm yogurt (at room temperature); 1/2 cup grated cheddar; 1/4 cup freshly minced parsley; Lots of fresh black pepper; Extra cheddar (for the top); Paprika (for the top)