Lemon Curd Filling

In a 1 1/2 quart heavybottomed saucepan, whisk briefly to combine the eggs, egg yolks, sugar, lemon juice, and lemon zest. Add the pieces of butter, and place the saucepan over medium heat, stirring constantly over the entire bottom. Cook the mixture without boiling until it begins to developbody and thicken. Remove from heat and pour through a stainless steel sieve into a bowl. Cover the surface with plastic wrap, poke a few small slits in the plastic with the tip of a paring blade allowing steam to escape while