Melt butter in saucepan, add the flour and simmer.
Stir in warmed milk, bring to boil and cook for 3 mins.
Add sugar and 5 egg yolks.
Cover and set in cool place until ready to oven.
Beat in Grand Marnier.
Grease and collar a soufflé dish.
Fold in beaten whites.
250° for 25 mins