Dissolve 1/4 cup cornstarch in 1/4 cup cold water.

Boil 1 1/2 cups water and add cornstarch mixture along with:

1 1/2 cups sugar
1 T. butter
2 T. lemon zest

Cook over medium heat until mixture clears.
When cool, beat in:

2 eggs
1/4 cup lemon juice

Proceed as for any 2 crusted pie.