Prep the basil properly: Wash the basil and dry thoroughly — salad spinner, then patted with a clean towel. Wet basil turns pesto muddy and dark. Discard any bruised or blackened leaves.
Blitz for 45 seconds: Put basil, olive oil, pine nuts, Parmesan, salt and pepper into a blender or food processor. Pulse 45 seconds until smooth but not completely liquid — a loose sauce with some texture. Scrape down the sides once halfway.
Check the consistency: It should coat the back of a spoon in a glossy layer. If thicker, pulse in another splash of olive oil — never water.
Taste, seal and store: Adjust salt, pepper or Parmesan. Spoon into a small glass jar and pour a thin layer of olive oil over the surface to seal out air. Seal and refrigerate, or use straight away.
