- Chop the potatoes and place in cold salted water. Bring to the boil and cook until tender.
- Peel the beetroot and bring them to the boil in a separate saucepan, continue to cook until they are tender. Rinse well.
- Cool the potatoes and the beetroot and mix with the oranges, rocket and walnuts.
- Combine the lemon, mustard, olive oil and pour over the salad. Season with salt and pepper.