Preheat the oven to 220°C.
Heat olive oil in an ovenproof pan and sear the seasoned pork fillet for 3 minutes until browned.
Transfer the pan to the oven and roast the pork for 12 minutes.
Rest the pork in a warm place for several minutes.
Sauté the sliced onion in olive oil for 5 minutes until softened.
Add wine, vinegar, honey, sugar, and spices to the onion and season to taste.
Stir in the shredded cabbage and simmer for 20 minutes until tender.
Grate the potato and squeeze out moisture using a clean cloth.
Season the potato, form into two rounds, and fry in oil and butter for 5 minutes per side.
Slice the pork and serve on top of the rostis with cabbage on the side.