Combine eggs whites, sugar and cream of tartar in a stainless steel mixing bowl and place over simmering water.
Stir constantly until sugar is completely dissolved. Egg white should be barely warm.
Remove from heat and beat with an electric mixer until soft peaks form.
Spread meringue on top of pie filling. Bake for 10 to 15 minutes at 350 degree F or until meringue is browned. Cool and serve.