Parsnip, swede and horseradish mash

Peel and chop the parsnips, swede and three-quarters of the horseradish into equal-sized cubes. Place in a saucepan of cold water. Bring to the boil and simmer for 10 mins, until softened. Drain. Add salt and pepper, and 25g of the butter. Mash roughly, so the different vegetables still remain visible. Stir, then transfer to a serving bowl. Grate the remaining horseradish over the mash and add dots of the remaining butter. Serve, garnished with parsley.