In a large mixing bowl, mix flour and 3 tablespoons sugar.
In a saucepan, heat milk. Remove from heat and pour milk into flour little by little, beating until fully mixed. Return mixture to saucepan and set aside.
Beat egg yolks. Meanwhile, reheat milk mixture and continue beating, slowly pouring over egg yolks. Cook over low heat until sauce thickens.
Remove from heat and add butter. Mix orange zest with a pinch of sugar and add it to the mixture, along with Grand Marnier.
Preheat your Oster oven to 400°F.
In a separate mixing bowl, mix egg whites and beat together with salt, until soft peaks form. Add remaining sugar and beat until stiff peaks form.
Using smooth, enveloping movements, add yolk mixture to beaten egg whites. Pour mixture into containers of your choice, filling them to the brim.