Preheat oven to 200°C (180°C fan assisted ovens)/Gas Mark 6.
In a small oven-proof frying pan, melt the butter and sugar together to form a toffee like sauce. Stir in the chopped apple until it is thoroughly coated in the sauce.
Next place the Jus-Rol Puff Pastry Round on top of the mixture and transfer to the pre-heated oven. Cook for approx 20 minutes, until the pastry has risen and is golden.
Remove from the oven, gently release the pastry from the edge of the pan and place a plate over the top of the pan. Carefully turn the pan upside down so the tatin transfers to the plate, with the pastry on the bottom.
Spoon on any excess sauce and serve with a scoop of vanilla ice-cream.