Wash, peel and dice the potatoes. Put in a saucepan, cover lightly with water and bring to a boil. Then switch it down and cook for about 20 minutes.
miscellaneous
Take a pan and heat it with rapeseed oil. Rinse the pork tenderloin and pat dry with kitchen paper. Then cut into slices (medallions) and place in the heated pan. Fry for 1 or 2 minutes on both sides, then season with salt & gourmet pepper.
Preheat the oven to 160 degrees circulating air. Take a baking dish and put the pork fillet slices in it. Then put it in the preheated oven and finish cooking for about 12 minutes.
garnish
In the meantime, peel the vegetable onion and apple. Slice the onion into thin rings and pass the apple through a divider that will split it. Squeeze the juice from half a lemon. Take another pan, heat rapeseed oil in it and cook the onion rings and apple wedges in it. Season with lemon juice, honey and salt, let simmer again.
Serving
Take the pork fillet slices (medallions) out of the oven. Take one or more flat plates and place the mashed potatoes in the middle. Put the cooked side dishes on top, garnish with the medallions. Chop the parsley and sprinkle it all around the plate, serve immediately.