Make pastry: Beat butter, sugar and egg yolk in a small bowl with an electric mixer until combined. Stir in sifted flour and ground almonds. Knead dough on a floured surface until smooth. Enclose pastry in plastic wrap; refrigerate for 30 minutes.

Peel, quarter and core apples; cut into 1cm pieces. Combine apple, caster sugar and ½ cup of the water in a large saucepan; cook, stirring, until sugar dissolves. Bring to the boil. Reduce heat; simmer, covered, for 3 minutes. Uncover; simmer for 2 minutes or until apple is tender. Stir in combined cornflour and the remaining water; cook, stirring, until mixture boils and thickens. Stir in blueberries. Remove from heat. Cool.

Preheat oven to 200°C.

Roll pastry between sheets of baking paper until large enough to line a deep 24cm round loose-based fluted flan tin. Ease pastry into tin, press into base and side; trim edge. Place tin on an oven tray; refrigerate 20 minutes.

Line pastry with baking paper; fill with dried beans or rice. Bake for 15 minutes. Remove paper and beans; bake for 10 minutes or until browned lightly.

Meanwhile, to make crumble mixture, combine oats, cinnamon, flour and brown sugar in a medium bowl; rub in butter. Stir in nuts.

Spoon apple mixture into pastry case; top with crumble mixture.

Bake pie about 35 minutes. Stand for 15 minutes before serving.