Blend basil, oil, pine nuts, garlic and salt until smooth. This can be done most easily in a blender (stop once or twice to stir contents), food processor or large mortar and pestle. When evenly blended, scrape into a bowl and stir in cheese. Store, covered with a film of olive oil, in a screw-top .
As a Pasta Sauce
Thin the desired quantity of pesto with a spoonful of pasta cooking water (this helps the sauce to combine much more readily with the pasta), then toss with hot cooked pasta.
Note: the pesto recipe above makes enough pesto for approximately 500g pasta.