1. Preheat oven to 325 degrees Fahrenheit (170 degrees Celsius). Season roast with a bit of salt and some freshly ground black pepper.
2. In a large Dutch oven, heat two tablespoons oil and sear the meat on both sides, about four to five minutes on each side. Remove the meat and set aside. Add onions, carrots, celery, and garlic to the pot and sauté for about five minutes or until just softening. Add wine, ketchup, and sugar; stir. Let cook for five more minutes.
3. Return the meat to the pot. Combine the horseradish and celery root with the two remaining tablespoons oil and pat over the top of the meat to coat it.
4. Cover meat and bake in the oven for an hour and a half. Remove from oven and let cool. Slice into thin slices across the grain. Before serving, rewarm for approximately one and a half hours.