Preheat oven to 375 degrees F.
Scald the milk and set aside.
In a medium sauce pan, combine the butter and flour, cook to a light blonde color, making a light roux. Off of the heat, whisk some of the scalded milk into the roux, slowly incorporating all of the milk. Return the roux to a low flame, and whisk in 3/4 cup of sugar, orange juice concentrate, orange juice, vanilla, salt, bring to a boil remove from heat. Stir in the zest and orange liqueur. Carefully add some of the scalded milk mixture to the egg yolk, to balance the temperature, and then combine them both, whisking thoroughly. Cover, set aside, and cool.
Prepare 6 (12-ounce) souffle cups by buttering them lightly and dusting them with sugar.
Beat the egg whites to medium stiff peaks, add the remaining sugar, and beat to stiff peaks. Fold the milk and egg mixture into the beaten egg whites. Fill the buttered and sugared souffle cups about 3/4 of the way. Bake, in a water bath, until puffed and golden, about 12 to 15 minutes.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Swiss Lakewood Lodge, Lake Tahoe, CA