Preheat the oven to 190˚C/gas mark 5. Cover the beetroot with foil and place in the oven until tender, approximately 1-1 1/2 hours. Allow to cool, then peel with a small knife while still slightly warm. Cut into large cubes

Meanwhile, dice the sweet potato into cubes the same size as the beetroot. Lightly season with salt and coat with olive oil. Place on a baking tray and into the oven until tender, approximately 40-60 minutes

Heat a pan over a medium to high heat. Add the butter and once it begins to foam add the roast beetroot and sweet potato. As soon as the vegetables are heated through, season with salt and remove the pan from the heat. Serve immediately