Pesto is not an exact science.
Pesto is simple but tricky: you MUST have at hand top ingredients!
You need the best Italian (better genovese) basil you can find, better home grown from seeds, the best pine nuts, the best pecorino, garlic and very good not too fruity extra verging olive oil.
Stated this it is pretty much how it looks in the picture:
– loads of basil leaves, freshly picked. By loads I mean several plants, stalks removed;
– 1 or 2 garlic gloves, depending on taste;
– Pine nuts, fresh and crunchy, 1 or 2 handful;
– Finely grated pecorino, medium aged, not too old and tasty, but to young either.
Whiz all this on pulse mode.
Beginning to add extra virgin olive oil, little by little, until you have a thick paste. Taste. Add more basil/garlic/pine nuts/pecorino/oil to taste.
Do not worry if it looks to thick: you can always diluted with some warm water form the pasta pan.
It doesn’t last long, as it tends to get darker. Make it while the water for your pasta is going to boil.