Preheat the oven to 180°C, 350°F, Gas 4.
Bake the potatoes for 1-1½ hours until the flesh is soft.
Heat the oil with 1 tbsp of the butter in a large frying pan over a high heat then add the sausages, reduce the heat and cook for 10 minutes, turning to brown all over.
Add the honey and mustard and cook for a further 5 minutes.
Core the apples and cut into wedges. Push the sausages to the edge of the pan and add the apple wedges. Cook for about 2 minutes each side until turning golden.
Remove the sausages and apple with a slotted spoon and drain on kitchen paper. Keep warm.
Add the onion to the pan and cook for about 6-8 minutes, stirring until softened. Stir in the flour and cook for 1 minute then gradually add the wine, the Worcestershire sauce and half the stock. Stir until smooth. Add the remaining stock and allow to bubble for a few minutes to thicken. Return the apple to the pan and season.
Cut the potatoes in half and scoop the flesh into a bowl. Add the milk and remaining butter and mash until well combined. Add the herbs and season.
Divide the mash between 4 warmed plates, top with the bangers and spoon over the gravy.