To make the shortcake pastry, put the flour, sugar, semolina, butter and salt into a food processor and whizz until it resembles bread crumbs. Add the vanilla essence and the egg yolks and whizz again until the mixture starts to come together. Knead lightly and use to line a 23cm fluted tart tin. Bake for 15 minutes. Meanwhile, make the pastry cream filling. Whisk the egg yolks and sugar with the vanilla essence until smooth and well blended. Incorporate the flour and the corn flour into the egg mixture. Bring the milk just to the boiling point, remove from heat. Pour halve of the milk over the egg mixture and whisk well. Return this mixture to the remaining hot milk and whisk again. Return the mixture to the heat and cook until cream is thick. Finish with the liqueur and allow to cool before using. To assemble, fill the tart with the pastry cream filling and decorate with the fresh strawberries. Garnish with mint springs and dust lightly with icing sugar before serving.