1.Preheat oven to 180°C (160°C fan-forced).
2.Wash beetroots, trim stems. Place beetroots in a baking dish; add water. Cover dish tightly with foil; roast for about 1 hour or until tender.
3.Rub skins off beetroots; cut into halves. Put half the watercress onto a plate. Top with beetroot, remaining watercress and walnuts. Drizzle with combined oil and vinegar. Season with salt and freshly ground black pepper.
Not suitable to freeze or microwave.Note