Start by placing half of the frozen strawberries and all of the juices in the bag into a pan with 1 tbsp sugar and cook down for 10 minutes. Allow to cool then blitz into a sauce. You will need 4 large glasses for this recipe. Whip the cream with the icing sugar and vanilla to stiff peaks. Add in the crumbled meringues and the strawberry sauce and mix roughly. Spoon the mixture into the glasses, adding in the blueberries and remaining half of the strawberries at different intervals. Decorate the top and serve immediately.