Marinate steaks in a bowl with wine and thyme, then chill overnight.
Preheat the oven to 160°C.
Fry chopped carrots, celery, and onion in rapeseed oil until golden-brown.
Stir in garlic, tomatoes, and Worcestershire sauce.
Place steaks over vegetables, season, add marinade and stock, then boil.
Cover with greaseproof paper and bake for 90 to 105 minutes until tender.
Remove meat and whisk creamed horseradish into a ladle of the braising liquid.
Strain the liquid into a saucepan, simmer to thicken, and stir in butter and parsley.
Heat deep-frying oil to 180°C.
Mix flour with smoked paprika and place milk in a separate bowl.
Double-coat onion slices in flour and milk.
Fry onions for 1 to 2 minutes until golden and crisp.
Serve steaks with sauce, fried onions, and buttered boiled potatoes.