Spinach Souflé

1 lb spinach

½ cup butter

½ cup flour

2 ½ cups milk

8 egg yolks

10 egg whites

1 tsp salt

pinch of cream of tartar

¼ grated gruyere cheese

¼ cup coarsely chopped ham

Grease and flour a 2 qt. soufflé dish. Make sauce - add egg yolks 1 at a time off heat. Return to heat, cook till very thick, add squeezed and finely chopped spinach. Beat whites with salt and tartar till firm peaks form. Blend 1 cup of whites with white sauce. Then fold mixture into whites, add ham and cheese. Pour into dish; make a circle with a knife in the center of the dish.

Bake at 375F, pre-heated, for 40 minutes for 2 qt. dish, or 25 to 30 minutes for 2 1qt. dishes