Rinse the corned silverside in cold water to remove any surface brine. Place the corned silverside in a large heavy based pot, large enough for the meat to be completely submersed in water. Cover the silverside with cold water.
Place over a low heat and bring to just a simmer. Skim any scum that rises to the surface. Once all scum is removed, add onion with cloves, bay leaves, sugar and vinegar.
Partially cover and keep the heat at simmering point, small bubbles will occasionally rise to the surface. Adjust the heat throughout the cooking time.
Cook until the silverside is tender, about 1 ½ - 2 hours, adding potatoes for last 30 minutes of cooking time. A fork should easily penetrate the centre of the meat and potatoes should be tender.
Meanwhile to make the sauce, heat butter in a medium saucepan over medium heat. Add flour and cook stirring, for 1 minute. Gradually start adding milk, stirring constantly until all the milk is combined and sauce is smooth. Cook stirring, until sauce comes to the boil and thickens, simmer for 2 minutes. Stir through horseradish and parsley, season to taste with salt and pepper.
Slice silverside against the grain. Serve with the potatoes, steamed greens and drizzle with the horseradish sauce.
Tips
Cooking the potatoes in the braising liquid adds flavour to the potatoes.
Chopped fresh chives also work well in the horseradish sauce.
You can substitute the butter with olive oil spread and milk with soy milk in the sauce for a dairy free version.
