2) Whisk the vinegar with salt and pepper, to taste, in a large bowl. Whisk in the olive oil in a slow steady stream to make a dressing. Toss the cut beetroot in the dressing; set aside to marinate for at least 15 minutes or up to 2 hours.
3) Preheat the oven to 180C/Gas Mark 4. Spread the nuts on a baking sheet and oven-toast, stirring once, until golden brown, about 8 minutes. Cool.
4) Toss the rocket and escarole with the beetroot and divide among 4 plates. Scatter the walnuts and goat cheese on top. Serve.