Preparation. This lamb recipe is bursting with flavour, thanks to the potato rosti and pea puree. Try Mary Berry's popular bacon-studded Grated, fried potatoes make a super side dish or a great base for brunches. Peel the potatoes and grate them, using the large holes of a hand grater or a food processor. Put the potatoes in a large bowl, add the salt and pepper, and toss to coat thoroughly. Let the potatoes rest for at least … From Fiona Maher for Masterchef Ireland. Potato, parsnip & horseradish baked rosti 3 ratings 4.4 out of 5 star rating A trio of winter vegetables that are the perfect accompaniment to a meal.