1 Cook the potatoes in salt water for around 25-30 minutes until fork-tender. Drain and leave to cool. Cut into quarters or eighths, depending on their size.
2 Fry the chorizo in a hot pan, add the onion and potatoes and continue to fry until golden brown. Remove from the heat.
3 Mix together the balsamic vinegar and the olive oil. Add the rocket and season with salt and ground black pepper. Add the chorizo and potatoes and mix carefully.
4 Season with coriander and arrange on plates. Serve topped with freshly grated Parmesan.