Step 1

Preheat oven to 250 degrees F ( 120 degrees C).

Step 2

Beat egg whites until stiff. Add cream of tartar and gradually add 1 cup sugar; beat until glossy. Turn the meringue into a well-greased 10 inch pie plate. Spread over bottom and sides of plate, building up the sides 1/2 inch above the edge of the plate. Place in oven, and bake 1 1/2 hours. Turn off oven, and leave meringue inside to cool slowly.

Step 3

Combine egg yolks, 1/2 cup sugar, 2 teaspoons zest, and lemon juice in double boiler. Cook, stirring constantly, over medium low-heat until thick. Pour into a bowl and cool thoroughly.

Step 4

Whip cold cream until stiff. Place half of the whipped cream in the cooled meringue shell. Cover with a layer of the lemon filling and top with the remainder of the whipped cream. (This top layer can be piped on with a decorative star tip). Garnish with remaining lemon zest. Refrigerate until serving.