Top with another pastry and spread with about 1/4 cup of the pumpkin mixture.

Pour the pumpkin mixture into the prepared crust.

Line a 9-inch pie pan with pastry for the bottom crust and spoon in the pumpkin mixture.

Spread half the dough with the pumpkin mixture, coming to within 1 inch of the edges.

Make a paste of the cornstarch and lemon juice and beat into pumpkin mixture.

Cut the frozen pumpkin mixture into small cubes and, a few at a time, puree them in a food processor until they are smooth.

Stir 1/3 of the egg whites into the pumpkin mixture and fold in the remaining whites.

Gently but thoroughly fold the beaten whites into the pumpkin mixture.

Pour the hot pumpkin mixture into the egg mixture.

Cover with 1/2 of the pumpkin mixture.