Pound the pesto ingredients to a paste
in a pestle and mortar or food processor.
Cook the pasta. Drain, return to the pan
with the pesto and stir over a low-ish
heat for 2-3 mins – not any longer or the
sauce will go grey. Add the spinach and
stir well for 1 min until it wilts. Add the
walnuts, rocket, parsley, sage, chives,
basil and tarragon, if using, and oil. Take
off the heat and stir well before serving
sprinkled with grated Parmesan.