1. Into a large pot of boiling salted water, add the pasta and cook as per packet directions.
  2. Add potato into the pot to cook with the pasta.
  3. To make the pesto, add pistachios and rocket into a food processor and blitz.
  4. Add Parmesan and blitz again.
  5. Slowly pour olive into the food processor until the pesto is smooth and add salt and pepper.
  6. Once the pasta and potatoes are cooked, drain and reserve ½ cup of the cooking water.
  7. Return the pasta and potatoes to the pot, pour in pesto and gently mix to combine.
  8. If necessary, add small amounts of cooking water to loosen the sauce.
  9. Top with extra Parmesan before serving and enjoying with family and friends.