Preheat oven to 350 degrees F. Butter a 9 inch glass pie pan. Prepare the rice crust: Beat the egg until frothy, Add rice and cheese and stir well. Spread this mixture in the buttered pie pan. Set aside.
Cook the spinach according to package. Drain thoroughly, pressing all the liquid out through a stainer. Place the drained spinach in a bowl and add the butter; set aside.
In a large bowl; beat the eggs until frothy. Stir in the cottage cheese, cream, mustard, seasonings, and grated cheeses. Stir until well mixed. Add the buttered spinach and stir again until well mixed. Pour into the rice crust.
Baked about 40 minutes, until puffed, golden brown and set in center. (Check the center to be sure it is no longer liquid) Allow to cool 5 minutes. Slice and serve