Preheat the oven to 180 degrees C. Place the flours and caster sugar in a food processor and process until combined. Add the butter. Process in short bursts until the mixture resembles coarse breadcrumbs. Add egg and process in short bursts until dough just clumps together, adding a little cold water, if necessary.
Turn dough out onto a sheet of baking paper and roll out to a 25cm round. Transfer, on the paper, to a large baking tray. Sprinkle almond meal over pastry, leaving a 3cm border.
Place the berries into a bowl and sprinkle icing sugar cornflour and cinnamon over berries and toss to combine. Stand for 2 minutes, and then toss again until the cornflour has dissolved into the juices. Pile berry mixture onto the pastry, leaving a 3cm border around the edge. Fold the pastry edges in to partially enclose and create a border over the filling. Sprinkle with flaked almonds.
Bake tart for 30-35 minutes or until the pastry is lightly browned and crisp. Cool on tray for 10 minutes. Cut into wedges to serve.