To roast the beetroot pre-heat the oven to 180c 375f.
Drizzle the beetroot with olive oil and salt and pepper.
Wrap in foil and roast in the oven for about 30 minutes, or until tender.
Once cooked, remove from the oven and leave to cool for about 20 minutes.
Once cooled, peel the beetroot and cut into quarters.
Mix all the ingredients for the vinaigrette and whisk well.
Place all the salad ingredients on a serving platter and drizzle with the vinaigrette and scatter with the walnuts.
Serves 4 as a side or 2 as a dinner or lunch