Ingredients for 4 persons:
Fresh Basil leaves -                        about a pound and a half to two pounds
pine nuts -                                   3/4 cup
Romano cheese (grated) -               one cup
Olive oil (extra virgin) -                enough to make the sauce the correct consistency

How to do it:
Wash the basil well.
Remove the basil leaves from the stalks and discard the stalks.
Put the basil in a blender a little at a time and grind until liquefied (grind all the basil).
Add the pine nuts to the basil and grind again until the pine nuts are also liquefied.
Add the romano cheese and mix well in the blender.
Add the olive oil, a little at a time (while the blender is on) until you have a thick sauce consistency.
Pour over cooked spaghetti. Sprinkle a little more grated cheese on top and enjoy.