Stir together in a saucepan, and heat through
1 1/2 c pumpkin
8 oz sour cream
3/4 c sugar
3 egg yolks
2 teaspoons pumpkin pie spice
Now, in a separate bowl, beat the 3 egg whites with 1/4 teaspoon cream of tartar and 1/4 c sugar until you have stiff peaks.
Fold the two together GENTLY so you don't ruin all that hard work, and pour into your pie crust.
Bake at 350 for 50 minutes.