Peel the potato and parsnip, grab a bowl and grate them both into it. Grate or finely slice the sprouts and chuck them into the bowl too. Put the veg in a sieve and squeeze out as much liquid as you can. Return the mixture to the bowl and crack in the egg. Mix and season, then add your rosemary and garlic.
Now it’s time to get your hands messy. Shape the mixture into three rösti patties, equal in thickness. Slice the leftover turkey breast. Put it in a pan with the gravy on a low heat and simmer until the turkey is warm. Heat the coconut oil in a separate frying pan. Cook the röstis for 3 mins each side until golden brown, then put them on a plate, layer with the sliced turkey and add a dollop of cranberry sauce on top. Voilà – a lovely, lean Christmas leftover meal!