Put the potatoes on to boil. While they are boiling, season the steaks on both sides.
Warm a frying pan on medium/high heat. Add a little cooking oil to the pan. Add the steaks and fry until cooked to your liking, then remove and leave to rest.
When the potatoes are cooked, drain them then mash them with the butter, Horseradish Sauce and some salt and pepper.
Slice the steaks once they have rested and serve with the potatoes and fresh steamed vegetables on the side.