Combine crumbs, butter and sugar and press the mixture into a 9-inch
pie plate. Chill.
Sprinkle gelatine over lime juice and let the mixture set for a
few minutes until it is soft.
Beat egg yolks in the top of a double boiler and add 1/2 cup of
the sugar and the lime zest and continue beating. Add gelatine and
continue cooking over the boiling water, stirring constantly until
the mixture is slightly thickened. Pour this mixture into a bowl
and blend in the tequila and Cointreau. Chill this mixture for 30
Beat egg whites until frothy and foamy and gradually add the remaining
1/2 cup sugar; continue beating until stiff peaks form. Fold the
whipped whites into the chilled, cooked mixture and pour into the
crust and chill until set, about 5 hours.