Lemon Filling (for Blitz Torte, Etc.)
Blend flour, sugar and salt in a saucepan; add water, stir until smooth. Place over moderate heat, stir constantly until thick and clear. (7-8 min.) Beat egg yolks, add a little hot mixture, beat thoroughly, return to saucepan, stir vigorously; and cook another 2 min. Remove from heat. Blend in rind and butter, then lemon juice.
Cool. From Meta Givens Modern Encyclopedia of Cooking.