Bring 2 tablespoons sugar, water and Maille Honey Dijon Mustard to a boil in small saucepan, stirring occasionally. Reduce heat and simmer, stirring occasionally, until sugar is dissolved and mixture thickens to a light syrup, about 5 minutes. Let cool.
Beat egg whites with water with electric mixer or wire whisk in small bowl until stiff peaks form. Gently stir in Mascarpone and remaining 1 tablespoon sugar. Spoon ½ of the mixture equally into 4 glass dessert dishes.
Dip lady fingers into syrup, then arrange 2 in each dish on Mascarpone mixture. Top evenly with remaining Mascarpone mixture, then berries. Refrigerate at least 1 hour before serving.