Roll out a store-bought, preferably ready-rolled puff pastry dough (non-butter/vegan versions are widely available) to a large rectangular (approximately 350mm x 225mm), and place on a baking sheet.

Using a knife, lightly mark out a thin frame on all sides of the pastry (approximately 1cm thick). Mark the frame with thin lines using the back of a fork. 

Avoiding the frame, fork the base of the pastry with the tips of the fork (this will ensure no air bubbles during cooking). Baste with a little melted apricot jelly or jam (no bits). This will keep the pastry crisp.

Avoiding the frame, spread a thin layer of sweetened apple sauce across the pastry base (around ½ cup). 

Peel, halve, core and thinly slice around 6 firm apples (you may need a couple extra). Avoiding the frame, lay them out in rows (vertically, down the short side). When done, sprinkle with some cinnamon and granulated sugar.

Baste the frame with a beaten egg yolk. 

Bake at 180c for around 30 minutes, till nicely golden. 

Glaze with some melted jelly/jam before cutting into slices, and serving.

Serves 4-5.