Trim the pork fillet from any excess fats, hold flat on a chopping board with the palm of your hand and push a sharp knife through the centre to hollow the fillet till the end taking care not to cut through. 

Peel and grate the apples and mix together with the chopped bacon, apricots, sultanas, parsley, thyme, lemon zest, ginger, orange juice and bread crumbs. Push the obtained mixture into the fillet. 

Season the pork with salt, pepper and Aromat. Seal in a hot pan with melted butter and more thyme springs. Transfer to a baking tray and finish cooking in a hot oven for approx. 25 minutes.

To make the Duchess potatoes,  finely chop the mushrooms and cook together with the garlic clove in a knob of butter, bind with the tomato passata, season with salt, pepper and Aromat.

In a separate recipient, mixed the mashed potatoes with the yolk, salt, pepper, Aromat and grated cheese. Pipe the obtained mixture into a vol au vant shape. Fill with the mushrooms filling, brush with melted butter, sprinkle with extra cheese and bake till golden in a hot oven. 

Serve the pork sliced accompanied with the duchess potatoes.